Erev Pesach that Falls out on Shabbat (1)
Halakha: A Weekly Shiur In Halakhic Topics
Yeshivat Har Etzion
EREV PESACHTHAT FALLS OUT ON SHABBAT (PART 1)
By Rav Yosef Zvi Rimon
TA'ANIT BEKHOROT (THE FAST OF THE FIRSTBORNS)
When Erev Pesach falls out on Shabbat, Ta'anit Bekhorot also falls out on Shabbat. We must, therefore, examine whether the fast should be advanced, delayed, or cancelled altogether. The Gemara (Chagiga 5a) explains that when Tish'a Be'av falls out on Shabbat, we delay the fast until Sunday, rather than observe it earlier, for "we do not advance [the commemoration] of a calamity." Based on this, the Halakha has been established that fasts that do not commemorate a tragedy - like Ta'anit Bekhorot or Ta'anit Esther - are moved up and observed earlier, whenever they fall out on Shabbat (see Responsa Maharil, no. 110).
SHOULD THE FAST BE OBSERVED ON THURSDAY OR FRIDAY?
The Rambam discusses this question with respect to Ta'anit Esther, ruling as follows (Hilkhot Ta'aniyot 5:5):
If the thirteenth of Adar falls out on Shabbat, we observe the fast already on Thursday, the eleventh [of Adar].
It would seem that if Ta'anit Esther is moved up to Thursday, then Ta'anit Bekhorot should be moved up to that day as well. There may, however, be a special reason for advancing Ta'anit Esther to Thursday. The Maggid Mishne explains that Ta'anit Esther is not observed on Friday, because "we do not fast on Friday [so as not to diminish] the honor of Shabbat." This reason clearly applies in equal measure to Ta'anit Bekhorot.
In contrast to the Maggid Mishne, the Tur explains that Ta'anit Esther is moved up to Thursday on account of the many Selichot that must be recited on that day (Tur 686; so too the Rosh and the Ran):
When Purim falls out on Sunday - the fast is advanced to the previous Thursday, because we are accustomed to recite many Selichot and supplications on that day, and this is impossible on Friday, because people would be unable to prepare for Shabbat.
Both explanations seem to be difficult, for when Asara be-Tevet falls out on Friday, the fast is observed on that very day, and we are concerned neither about the many Selikhot said that day, nor about "not fasting on Friday because of the honor of Shabbat"! It may perhaps be argued that when a fast actually falls out on Friday, then we fast on that day, but when we are forced to move up the fast, so that in any event it will not be observed on its designated date, we do not advance it to Friday, so as not to enter Shabbat while fasting (see Maggid Mishne, ibid.)
There is a practical difference between the two reasons relating to Ta'anit Bekhorot: According to the Tur's reason, Ta'anit Bekhorot should be observed on Friday, for no Selikhot are recited on Ta'anit Bekhorot, whereas according to the Maggid Mishne's explanation, the fast should be observed on Thursday, because fasting on Friday would diminish the honor of Shabbat.
The Me'iri rules (in his Magen Avot; see Bet Yosef 470:4) that Ta'anit Bekhorot is moved up to Friday. According to most Rishonim, however, the fast is observed on Thursday. This ruling is found in Midrash Tanchuma (Bereishit, 3); Responsa Terumat ha-Deshen (I, 126); the Maharil (nos. 110 and 158); and elsewhere.
The Terumat ha-Deshen brings an opinion that when Ta'anit Bekhorot falls out on Friday, the fast is not observed at all (Responsa Terumat ha-Deshen, ibid.; and so too Agur, 771, in the name of his father, cited in the Bet Yosef, 470).
According to one of the Terumat ha-Deshen's teachers, proof may be adduced from the Yerushalmi that when Erev Pesach falls out on Shabbat, there is no need to fast at all. The Yerushalmi (Pesachim 10:1) reports that Rav Yehuda ha-Nasi did not eat on Erev Pesach. The Amoraim disagree whether he acted in this manner because he was a firstborn, or because he was a particularly fastidious eater and he wanted to preserve his appetite for the matza that would be eaten later that night at the Seder. Now, it should have been possible to find out whether Rav Yehuda ha-Nasi acted in this manner even when Erev Pesach fell out on Shabbat, and thus decide the matter: If he fasted because he was a fastidious eater, then clearly he would not have observed the fast when Erev Pesach fell out on Shabbat (because the fast would not be directly followed by the Seder). Therefore, if Rav Yehuda ha-Nasi fasted even when Erev Pesach fell out on Shabbat, then it must be that he fasted because he was a firstborn, and if not, then his fast in ordinary years must have been because he was a fastidious eater. The fact that the Yerushalmi did not decide the matter in this way, proves, according to the Terumat ha-Deshen's teacher, that Ta'anit Bekhorot is not observed when Erev Pesach falls out on Shabbat.
In his conclusion, the Terumat ha-Deshen himself rejects this position, and suggests that the Amoraim may have forgotten how Rav Yehuda ha-Nasi had conducted himself when Erev Pesach fell out on Shabbat, just as Benei Betera had forgotten the law in a similar case:
Benei Betera were nesi'im, and yet they forgot the law regarding Erev Pesach that falls out on Shabbat, whether or not the paschal offering sets aside Shabbat. How could they have forgotten what had been done in earlier years? You must say, then, that for many years, Erev Pesach had not fallen out on Shabbat, and that they forgot the matter, even though it had ramifications for the community at large. We can certainly say then about a matter relating to a single individual that had been forgotten, that in his days too, Erev Pesach had not fallen out on Shabbat for many years.
The Shulchan Arukh rules as follows (Orach Chayyim 470:2):
If Erev Pesach falls out on Shabbat, some say that the firstborns fast on Thursday, while others say that they do not fast at all.
Rema: A person should conduct himself in accordance with the first opinion.
The Shulchan Arukh records both opinions, without explicitly deciding between them, though his formulation implies that he himself maintains that there is no need to fast at all. For the rule is that when the Shulchan Arukh says "Some say while others say ," the law is in accordance with the second opinion. Responsa Yechave Da'at (I, no. 91) adds that it is recommended that a firstborn participate in a se'udat mitzva (a feast marking a religious milestone), and exempt himself thereby from fasting. On the other hand, the Rema rules that the fast should be observed on Thursday, as do many Acharonim: (Rav Tykocinski (Lu'ach Eretz Yisrael), Ben Ish Chai (year 1 96, 1), and others.
PARTICIPATING IN A SIYYUM (CELEBRATION OF THE COMPLETION OF A TALMUDIC TRACTATE) IN ORDER TO EXEMPT ONESELF FROM FASTING
The Acharonim disagree whether in an ordinary year a firstborn may exempt himself from observing Tan'anit Bekhorot by participating in a se'udat mitzva. There are those who are stringent, arguing that a se'udat mitzva does not exempt the firstborn from fasting (Noda Biyehuda, Mahadura Tinyana, Kuntrus Acharon, no. 354; Chatam Sofer, Rav Kook). Others rule leniently and permit a firstborn to exempt himself from the fast (Mishna Berura, 470, no. 10; Responsa Iggerot Moshe, Orach Chayyim, I, no. 157; Responsa Minchat Yitzchak, III, no. 93, Responsa Yabi'a Omer, IV, Orach Chayyim, no. 13; and others).
When Erev Pesach falls out on Shabbat, some authorities see a reason for greater stringency, while others see a reason to be lenient. Rav Frank (Mikra'ei Kodesh, Pesach, II, no. 23) writes that those who are lenient in an ordinary year base their leniency on the concern regarding the possible adverse effects of fasting on that night's seder. When, however, the fast is pushed up to Thursday, so that there is no concern of this sort, the firstborns should fast. Similarly, there are Acharonim who argue that even if there is room for leniency in an ordinary year, because owing to the seder, one cannot eat immediately at the end of the fast, when the fast is pushed up to Thursone can eat right after nightfall, one should be stringent.
In contrast to these opinions, most of the posekim rule that when Erev Pesach falls out on Shabbat, there is at least as much reason for leniency as in ordinary years, and perhaps even more so. These posekim rely on the opinion that when Erev Pesach falls out on Shabbat, there is no Tan'anit Bekhorot at all. This is mentioned in Responsa Iggerot Moshe (Orach Chayyim, IV, no. 69); Responsa Yechava Da'at (I, no. 91); and in Rav Tykocynski's Lu'ach Eretz Yisrael. The Mishna Berura does not distinguish between ordinary years and years in which Erev Pesach falls out on Shabbat with respect to a se'udat mitzva. Responsa Yechave Da'at writes that even a father who fasts on behalf of his firstborn son is totally exempt from fasting when Erev Pesach falls out on Shabbat.
To summarize: When Erev Pesach falls out on Shabbat, Ta'anit Bekhorot is observed on Thursday. Firstborns may practice leniency and exempt themselves from the fast by participating in a se'udat mitzva (the justification for doing so may perhaps be even greater than in ordinary years).
SEARCHING FOR CHAMETZ
The Rambam rules that when Erev Pesach falls out on Shabbat, bedikat chametz (the search for chametz) is performed earlier than usual (Hilkhot Chametz u-Matza 3:3):
If the fourteenth [of Nisan] falls out on Shabbat, we search for chametz on Thursday night, the night of the thirteenth [of Nisan].
The Shulchan Arukh (444:1) follows the Rambam, and so this year we search for chametz on Thursday night.
The procedure of the bedika follows that of other years: prior to the bedika we recite the berakha "al bi'ur chametz," and following the bedika we formally renounce and nullify the chametz ("bittul"), as is done in ordinary years (Taz, 444, no. 7; Mishna Berura 444, no. 1).
One who failed to perform the bedika on Thursday night should search for chametz on Friday morning, with a berakha (only if the search is conducted after Pesach is the blessing not recited). If he neglected to conduct the bedika on Friday morning as well, he should not search for chametz on Shabbat (It stands to reason, however, that if the electric lighting suffices for a search, he should search for chametz even on Shabbat). The posekim disagree whether he should perform the bedika on the night of the seder or the next night after Yom Tov. The Mishna Berura rules (435, no. 3; Sha'arei ha-Tziyyun, ad loc.) that if a person nullified his chametz on Shabbat prior to the end of the fifth [halakhic] hour of the day, he should search for chametz only after Yom Tov. If, however, he forgot and nullified his chametz only after the end of the fifth hour, he should perform the bedika on the night of the seder.
BI'UR AND BITTUL CHAMETZ -
DESTROYING AND NULLIFYING THE CHAMETZ
The Mishna in Pesachim deals with the question when must the chametz be destroyed when Erev Pesach falls out on Shabbat (Pesachim 49a):
When the fourteenth [of Nisan] falls out on Shabbat, all [the chametz] is destroyed before Shabbat; these are the words of Rabbi Meir. But the Sages say: At its time. Rabbi Eliezer bar Tzaddok says: Teruma [is destroyed] before Shabbat; non-sacred [chametz] at its time.
We see then that according to Rabbi Meir, the chametz must be destroyed on Friday, whereas the Sages and Rabbi Eliezer bar Tzaddok maintain that it must be destroyed "at its time," that is, on Shabbat itself. At first glance, the position of the Sages is astonishing: how can it be permissible to burn chametz on Shabbat?
The Ba'al ha-Ma'or (ad loc.) explains that according to Rabbi Meir, chametz can only be destroyed by way of burning, and so bi'ur chametz cannot be performed on Shabbat. The Sages, on the other hand, maintain that chametz may be destroyed even by way of crumbling and casting to the wind, and so bi'ur chametz can be performed even on Shabbat.
The Rambam rules that when Erev Pesach falls out on Shabbat, the chametz should be destroyed on Friday (Hilkhot Chametz u-Matza 3:3):
One should leave out chametz to eat until the fourth [halakhic] hour on Shabbat morning, and this is placed in a hidden place. The rest should be destroyed before Shabbat.
According to the explanation proposed by the Ba'al ha-Ma'or, we would have expected the Rambam to rule that chametz can only be destroyed by way of burning. In fact, however, the Rambam rules that bi'ur may be performed in many different ways (Hilkhot Chametz u-Matza 3:11):
How is bi'ur chametz performed? He burns it, crumbles it and casts it to the wind, or casts it into the sea.
Why then, according to the Rambam, do we not perform bi'ur chametz on Shabbat? This question relates both to the laws of Shabbat and to the laws of bi'ur chametz. Hence, we can answer the question from the perspective of the laws of Shabbat, or from that of bi'ur chametz, or from that of a combination of the two.
From the perspective of the laws of Shabbat: The Rambam may be of the opinion that crumbling bread on Shabbat is forbidden.
From the perspective of the laws of bi'ur chametz: The Rambam may have understood that the Tannaim disagree about the nature of bi'ur chametz.
The Minchat Chinukh (mitzva 9) analyzes the nature of the mitzva of tashbitu (destroying chametz - "But on the first day you shall have removed leaven out of your houses; Shemot 12:15): Must a person actively destroy his chametz, or does it suffice that on the fourteenth of Nisan there be no chametz in his possession?
The practical difference between these two understandings is whether a person who has no chametz in his house must go out and buy chametz in order to remove it. If the mitzva is active in nature, he should buy chametz, so that he can fulfill the mitzva; but if the mitzva is passive, there is no need to buy chametz for that purpose.
The Rambam may have understood that this is the issue at the heart of the Tannaitic dispute: Rabbi Meir maintains that the mitzva of tashbitu is passive in nature, and therefore even if a person destroys his chametz on Friday, he fulfills the mitzva on the fourteenth of Nisan. The Sages, on the other hand, understand that the mitzva requires a positive act, and therefore it should be performed on Shabbat, the fourteenth of Nisan, the time that a person is obligated to perform the mitzva.
According to this understanding, the Rambam rules like Rabbi Meir, and therefore - despite the fact that according to the Rambam it is possible for a person to destroy his chametz on Shabbat in a perfectly permissible manner by crumbling it and casting it to the wind - he prefers to rule that the chametz should be destroyed on Friday, for even in that way the mitzva of tashbitu is fulfilled in the best possible manner.
Combination of the laws of Shabbat and those of bi'ur chametz: Many Rishonim maintain that there is no prohibition of "grinding after grinding" on Shabbat. Why not?
1. Nothing new is created in the process.
2. The prohibition of grinding only applies to God's creations (such as fruits and vegetables), and not to human products (such as bread); this is the position of the Chazon Ish.
According to the first understanding, it is possible to say that generally speaking the prohibition of grinding does not apply to bread. On the fourteenth of Nisan, however, it does, for when a person crumbles the bread, he fulfills the mitzva of tashbitu, and so the crumbling of bread yields a new product! According to this understanding, the Rambam rules like Rabbi Meir that a person is forbidden to perform bi'ur chametz on Shabbat, even by way of crumbling the bread, despite the fact that on an ordinary Shabbat the crumbling of bread is permitted.
According to the explanations thus far presented, the Rambam ruled in accordance with Rabbi Meir, either because he maintains that even when a person destroys his chametz on Friday, he passively fulfills the mitzva of bi'ur on Shabbat, or because he believes that destroying chametz on Shabbat by way of crumbling constitutes a violation of the prohibition of "grinding" on Shabbat. One question, however, remains unanswered: Why did the Rambam rule in accordance with Rabbi Meir against thSage, rather than follow the rule that the law is in accordance with the majority opinion against the opinion of an individual sage? Indeed, the Ra'avad raised an objection to the Rambam, arguing that the law should follow the Sages who maintain that the chametz should be destroyed on Shabbat. The Bet Yosef (444) reconciled the Rambam's position, explaining that all agree - both Rabbi Meir and the Sages - that chametz should be destroyed on Friday. They disagree only whether it is permissible to leave a small amount of chametz for Shabbat: According to Rabbi Meir, this is forbidden, whereas according to the Sages, it is permissible to leave enough for two Shabbat meals, and then destroy whatever is left over on Shabbat. According to this explanation, the Rambam ruled in accordance with the Sages.
The Shulchan Arukh (444:1) follows the Rambam, that when Erev Pesach falls out on Shabbat, chametz is destroyed on Friday. One is, however, permitted to leave chametz for the Shabbat meals, and any chametz that is left over may be crumbled and thrown in the toilet (Bach 444), or doused with something that renders it inedible (see below).
BY WHAT TIME MUST THE CHAMETZ BE DESTROYED?
In an ordinary year, chametz must be destroyed by the end of the fifth [halakhic] hour of the day. It would seem that when bi'ur is advanced to Friday, a person should be able to destroy his chametz all day long, for even on Shabbat eating chametz is permissible, and so delaying its destruction of Friday should certainly not be forbidden. Nevertheless, the Mordekhai writes in the name of Rashi (Mordekhai, Pesachim, end of chapter 1) that even when Erev Pesach falls out on Shabbat - chametz should be destroyed by the end of the fifth hour of the day, as a precautionary measure to safeguard the practice in ordinary years. Following this ruling, the Shulchan Arukh also rules that one should conduct himself in this manner (444:2):
It is preferable to destroy [the chametz] on Friday before noon, so as not to make a mistake in other years and destroy [the chametz] after noon.
Based on this ruling, the Rogotzover (Tzafnat Pa'ane'ach, Hilkhot Chametz u-Matza 3:3) proposed a new interpretation of the Mishna, which also reconciles the Rambam's position: According to both the Sages and Rabbi Meir, chametz should be destroyed on Friday. According to Rabbi Meir, however, this may be done all day long, whereas according to the Sages, the chametz should be destroyed "at its time," that is, until the end of the fifth hour, as in an ordinary year. According to this explanation, the Rambam rules in accordance with the Sages, and there is no difficulty whatsoever with his position.
As was stated above, the bittul formula recited following bedikat chametz is recited on Thursday night after the bedika, as is done every year. As for the bittul chametz ordinarily recited in the morning, the Maharil (Hilkhot Bi'ur) writes that when Erev Pesach falls out on Shabbat, there is no need to nullify the chametz following the bi'ur. The Mishna Berura (444, no. 10, in the name of the Levush) explains that since chametz will still be eaten on Shabbat, there is no reason to perform bittul on Friday:
For this reason a person must nullify his chametz on Shabbat itself before the end of the fifth hour (Rema 444:2). It should be noted that even though we continue to eat chametz after the bi'ur (see Bei'ur Halakha 444, no. 1, s.v. u-meshayarin), and even on Shabbat itself, one should be exceedingly careful that following the bedika, all the leftover chametz is consolidated in one place, and not spread out over the house. This is especially important in a household with small children, where the danger exists that the chametz will become scattered throughout the house. Even though the "Kol chamira" formula is said only on Shabbat, those who are accustomed to recite the "Yehi Ratzon" passage at the time of the burning of the chametz, may do so on Friday when they burn their chametz (so writes Rav Sharya Deblitzki, in Erev Pesach she-Chal be-Shabbat). The question arises regarding someone who is not planning to eat any more chametz on Shabbat (see the solutions mentioned below) - may he recite the bittul formula already on Friday?
The Acharonim bring two reasons why we do not nullify the chametz on Friday following the bi'ur:
1. There is no reason to nullify it then, for in any case we continue to eat chametz (Mishna Berura 444, no. 10).
2. So that a person should not develop an adverse habit for the years to come, thinking that he may hold onto chametz even after performing bittul.
According to both reasons, if a person has no intention of eating any more chametz, and he is now burning all his chametz, he may recite the bittul now as well. In such a case, it is perhaps preferable to do so, for since he has no more chametz, he might forget to nullify his chametz on Shabbat. It may therefore be preferable to nullify it immediately after bi'ur chametz, as he is used to doing every year.
To summarize: When Erev Pesach falls out on Shabbat, bedikat chametz is moved up to Thursday night, and it is followed by the usual bittul chametz. On Friday morning, the chametz is burned before the end of the fifth hour, as in ordinary years. Bittul chametz is not performed at that time. (If, however, a person has no intention of eating any more chametz, he may perform bittul chametz following the bi'ur.) The chametz is nullified on Shabbat, before the fifth hour of the day.
THE SALE OF CHAMETZ
With respect to bi'ur chametz, we have seen that when Erev Pesach falls out on Shabbat, we are stringent and destroy chametz already on Friday before the time of bi'ur (the end of the fifth hour of the day), so as not to come to error in ordinary years. Does a similar concern exist with respect to the sale of chametz?
Responsa Maharam Shik (Orach Chayyim, no. 120) and Responsa Sho'el u-Meishiv (mahadura 6, no. 55) write that chametz should be sold on Friday by the fifth hour, so as not to come to any mistakes in ordinary years. On the other hand, Hagahot Maharsham (444, 2), Responsa Imrei Yosher (I, no. 146) and others write that in such a year chametz may be sold all day Friday before Shabbat. There is no concern about mistakes in ordinary years, for the sale of chametz is executed by Rabbis, rather than ordinary people. It is the generally accepted custom to sell the chametz at the end of the day (or at least to write in the contract that the sale will take effect at the end of the day - see below), for there are many stores that are still selling chametz at that time (challot for Shabbat, and the like).
There is still a difficulty, according to both opinions, for we continue to eat chametz on Shabbat itself! (There are those who refrain from eating bread on Shabbat for reasons of convenience, as we will see below, but one is certainly permitted to eat chametz that Shabbat, until the time when eating chametz is forbidden.)
There are two solutions to this difficulty. The first is to write in the bill of sale that the chametz that will be eaten on Shabbat is not included in the sale. This suggestion is put forward in Responsa Maharam Shik (ibid.) and in Responsa Har Tzvi (Orach Chayyim, no. 126). The second solution is to write in the bill of sale that the sale will take effect on Shabbat! According to this, the bill of sale is written on Friday (and it may be written during the fifth hour of the day as usual), but the transfer of ownership of the chametz to the non-Jew takes place only during the fifth hour of Shabbat!
This second solution is difficult, for the law is that we do not execute transactions on Shabbat! It was for this reason that many Acharonim did not accept this solution (Responsa Rabbi Akiva Eiger, no. 159; Responsa Ketav Sofer, no. 51; Responsa Maharam Shik, no. 205). Those who rule leniently on the matter argue that if the act that ultimately effects the transaction is performed before Shabbat, there is no problem if the transaction goes into effect only on Shabbat (see Responsa Iggerot Moshe, Orach Chayyim, III, no. 44).
To summarize: One is permitted to use chametz until the time of bi'uchamet, for according to some versions of the bill of sale, the chametz used on Shabbat is not included in the sale, and according to other versions, the sale goes into effect on Shabbat itself only after the time that chametz may no longer be eaten.
WORKING ON FRIDAY
The Mishna (Pesachim 50a) writes that one may not work on Erev Pesach after midday. The Rishonim disagree about the reason for the prohibition. Rashi explains (Pesachim, 50a, s.v. shelo la'asot:
So that a person should not be occupied in his work, and forget about destroying his chametz, slaughtering the paschal offering, and preparing matza needed that night.
In contrast to Rashi, who understands that working is liable to cause a person to forget about the special mitzvot of the day, the Yerushalmi explains that working on Erev Pesach is forbidden, because "it is not right that you should be engaged in your work while your sacrifice is being offered" (Pesachim 4:1).
There is a practical difference between these two reasons with respect to Erev Pesach that falls out on Shabbat: The paschal offering supercedes Shabbat, and therefore, even when Erev Pesach falls out on Shabbat, the paschal offering is brought on the fourteenth of Nisan. It seems then that according to the reason proposed by Rashi, working on Friday should be forbidden, for on that day a person must destroy his chametz and prepare all the things that he needs for the seder. According to the Yerushalmi, on the other hand, it should be permissible to work on Friday, for the paschal offering is not brought on that day:
The Bei'ur Halakha inclines towards leniency and allowing work on Friday, but does not issue a definitive ruling. Many Acharonim state explicitly that the custom is to be lenient, for most of the Rishonim bring the Yerushalmi's reason (Tosafot, Rosh, Ran, Rambam [Hilkhot Yom Tov 8:17]), and even according to Rashi's reason, there may be no reason to be stringent when Erev Pesach falls out on Shabbat. Thus write Maharil (Minhagei ha-Maharil, Hilkhot Erev Pesach), the author of the Kenesset ha-Gedola in the book Pesach Me'uvim (letter 93, cited by Sha'arei Teshuva, end of no. 444), Chida (Birkei Yosef), Responsa Yechave Da'at (I, no. 91), and others.
Following these posekim, it is customary to be lenient and work on Friday, even after midday, until the time of mincha ketana (nine and a half halakhic hours), like any other Friday (see Shulchan Arukh 251:1; Mishna Berura and Bei'ur Halakha, ad loc.). He who wishes to do so, may adopt stringency for himself (see Minhagei Maharil, ibid.).
RECITING "VIHI NO'AM" THE WEEK BEFORE PESACH
When Pesach falls out on Shabbat, many are accustomed not to say "Vihi No'am" the previous Motza'ei Shabbat, because working is forbidden on part of the fourteenth of Nisan (Friday), and therefore the week is not a full week of "our handiwork". When Erev Pesach falls out on Pesach, and working is permitted the entire day of Friday, "Vihi No'am" and "Ve'ata Kadosh" are recited on the previous Motza'ei Shabbat.
 Regarding this rule, see Responsa Yabi'a Omer, V, Orach Chayyim, no. 42, 2; ibid., Addenda, p. 349; VI, Choshen Mishpat, no. 2. Some authorities, however, express their reservations about this rule.
 Ta'anit Bekhorot is already mentioned by the Rishonim (see, for example, Rosh, Pesachim 10, sec. 19) in the name of the Yerushalmi (Pesachim 10:1), and in tractate Soferim (21:3). According to our reading in the Yerushalmi, however, there is no proof that firstborns fast, for Rabbi Yehuda ha-Nasi may have been accustomed to fast because he was a fastidious eater (see above, Yerushalmi, and Korban Netanel on Rosh, ibid.). The Rishonim may have understood that the Yerushalmi raised the possibility that Rabbi Yehuda ha-Nasi fasted because he was a firstborn, because it was the common custom for firstborns to fast on Erev Pesach; or they may have had a different reading in the Yerushalmi. Responsa Minchat Yitzchak (II, no. 93) cites those who read in tractate Soferim: "habekhorim mit'angim," "the firstborns indulge," instead of "habekhorim mit'anim," "the firstborns fast." Regarding this reading, see at length Responsa Yabi'a Omer, IV, Orach Chayyim, no. 13, and Responsa Yechave Da'at, III, no. 25 (which deals with the fasting of female firstborns).
 However, even Rav Frank adds in the name of Rav Kook that the ancillary fast (that which is pushed up to Thursday or Friday) cannot possibly be more stringent than the principal fast (that which is observed on its designated date). He seems to conclude that a firstborn may practice leniency and exempt himself from fasting by participating in a se'udat mitzva, for he writes that it is right to eat on Friday from the leftovers of the se'udat mitzva celebrated on Thursday - which implies that he accepts the leniency to participate in a se'udat mitzva even when Erev Pesach falls out on Shabbat.
 There seems to be room to say that a se'udat mitzva should be arranged on Friday as well, because somebody who refrains from fasting on Thursday because he is exempt on that day is obligated to make up the fast on Friday (as the Rema writes (686:2) regarding a circumcision performed on Ta'anit Esther that is pushed up to Thursday, that one should eat at the se'udat mitzva and fast on Friday). Some Acharonim write that one should be concerned about this (the Mo'adim u-Zemanim Haggada). Many others, however, rule leniently for a variety of reasons: First of all, one may rely on those who maintain that Ta'anit Bekhorot is not observed when Erev Pesach falls out on Shabbat. Second, it may be that the basis of the fast is to publicize the miracle that had been performed for the firstborns. Hence, even if a firstborn did not fast on Thursday, he is not considered as one who failed to fast and is therefore obligated to make it up the next day. For the se'udat mitzva on Thursday is treated like a fast, since it serves to publicize the miracle that had been performed for the firstborns, which is the goal of the fast (Responsa Arugot ha-Bosem, Orach Chayyim, no. 139). In addition, it is possible that the se'udat mitzva celebrated on Thursday extends to the following day as well (Responsa Chavat Ya'ir, no. 70, cited by Pitchei Teshuva, Yore De'a 217:16). It is for these reasons that a lenient ruling was issued by the Iggerot Moshe (Orach Chayyim, IV, no. 69); Kaf ha-Chayyim (470, 20); and see also Rav Frank's Mikra'ei Kodesh (Pesach, II, no. 23) and in the notes, Hararei Kodesh, ad loc.
 Why do we not search for chametz on Shabbat? The Shulchan Arukh ha-Rav (435:3) explains that the search is not performed on Shabbat, because the candle is muktze and may not be carried around the house. According to this, there should be room to suggest that a non-Jew carry the candle (see Responsa Avnei Yitzchak, no. 50 and Responsa Bet ha-Yotzer, Orach Chayyim, no. 18). Similarly, it may be argued that it should be permissible to carry the candle, because the positive rabbinic decree of bedikat chametz should set aside the negative rabbinic precept of moving something that is muktze. (following the Magen Avraham 446, no. 2, in the name of the Shela, that the rule that a positive commandment sets aside a negative commandment applies to rabbinic commandments as well). The Sedei Chemed (Ma'arekhet Chametz u-Matza 5, 14) deals with the issue, and proposes several answers: First, when a person picks up the candle, he has not yet started to perform the mitzva; second, moving muktze is a severe rabbinic prohibition, which is not set aside by an ordinary positive rabbinic commandment. Some Acharonim argue that today bedika is not performed on Shabbat even by way of a non-Jew, because we clean our houses in advance so thoroughly that they are regarded as "a place into which chametz does not enter," which does not require bedika. On the hand, it stands to reason that in today's circumstances when there is electric lighting, if a person forgot to perform bedika prior to Shabbat, he should search for chametz on Shabbat! And in places where there is insufficient lighting, he should complete the search after Shabbat.
 Circumcision supercedes Sha, but this because of a special derivation from a verse: "On the eighth day" - even on Shabbat. Regarding this issue, see Rav Yehuda Sheviv, "Erev Pesach she-Chal be-Shabbat," Ha-Ma'ayan 21, and in Batzir Avi'ezer, p. 278.
 Rabbenu Mano'ach (3:3) writes that crumbling bread is forbidden by rabbinic decree, but the Mishne le-Melekh (Hilkhot Chametz u-Matza 1:3) writes that it is forbidden by Torah law: "According to the Rambam, one is forbidden to crumble bread on Shabbat, it being a derivative of grinding."
 A similar analysis is found in Chiddushei Rabbenu Chayyim mi-Brisk on the Rambam (Hilkhot Chametz u-Matza 1:3).
 Indeed, the Rambam implies in Hilkhot Chametz u-Matza 2:1 that the mitzva of tashbitu may be fulfilled even prior to the fourteenth of Nisan. There is, however, a difficulty with this understanding, for the Rambam writes that any chametz that remains after the fourth hour of Shabbat should be nullified and covered with a utensil until after Yom Tov, at which time it should be destroyed. But according to this understanding, why should he not crumble the chametz on Shabbat? Perhaps we can combine this explanation with the previous explanation, or else say that he fulfills the mitzva of tashbitu even with bittul chametz (as the Rambam himself states in Hilkhot Chametz u-Matza 2:2).
 There is a slight difficulty with the Bet Yosef's explanation from what the Rambam says in the continuation, that any chametz that remains on Shabbat should be destroyed after Yom Tov but not on Yom Tov itself (see also previous note).
 The Shulchan Arukh writes "before noon," which seems to imply that one may be lenient about the additional hour - until the end of the sixth hour. The Maharsham (in "Da'at Torah) writes that in ordinary years, the chametz must be destroyed at the beginning of the sixth hour only because of a rabbinic decree. For this reason, the enactment only applies in ordinary years, when there is concern about the violation of a biblical prohibition. When, however, Erev Pesach falls out on Shabbat, the chametz may be burned until the end of the sixth hour. The Mishna Berura, however, writes that the Shulchan Arukh means to say that the chametz may be destroyed until the beginning of the sixth hour (i.e., until the end of the fifth hour, as in ordinary years). This is the position of most Acharonim, including Rav Tykocinski in his Lu'ach Eretz Yisrael, and the Chayyei Adam, 129, 9. Rav Frank writes in his Mikra'ei Kodesh (Pesach, I, no. 46, in Hararei Kodesh) that the wording of the Mishna Berura implies that chametz may be burned at the beginning of the sixth hour. He explains that in ordinary years chametz is burned at the end of the fifth hour, in order to allow time to recite "Kol chamira" before the end of the time that chametz is permitted. When, however, Erev Pesach falls out on Shabbat, and "Kol chamira" is recited not on Friday, but rather on Shabbat, the chametz may be burned even at the beginning of the sixth hour. As stated above, however, most Acharonim maintain that the chametz should be burned by the end of the fifth hour, as in ordinary years.
 This, however, involves a certain aspect of deception, for we do not define from the outset the precise portion of chametz that will be eaten on Shabbat. See Responsa Shevet ha-Levi, IX, no. 115.
(Translated by David Strauss)