The Mitzva to Eat on Erev Yom Kippur
In a number of passages, the gemara establishes that not only is it a mitzva to fast on Yom Kippur, but it is likewise a mitzva to eat on the day preceding it, erev Yom Kippur. The gemara appears to infer this mitzva from a verse in Parashat Emor (Vayikra 23:32), which demands that we begin the "inuy" (affliction, e.g., fasting) already on the ninth of Tishrei "You shall afflict your souls on the ninth of the month in the evening." Since the fast of Yom Kippur begins only on the tenth, this verse obviously refers to some aspect of the day that already starts on the ninth. The gemara determines that whoever eats on the ninth is considered as having fasted on both the ninth and the tenth.
Most Rishonim maintain that this mitzva is de-oraita, of biblical origin and authority, based on the aforementioned derivation from the verse. The Kesef Mishneh (Hil. Nedarim, ch. 3), however, suggests that the mitzva is only a rabbinic decree, while the verse serves merely as an asmakhta (allusion in the Biblical text).
An interesting question about the nature of the mitzva emerges from Rashi's various explanations of this law. In both Berakhot (8b) and Yoma (81b), Rashi explains that the purpose of the mitzva of eating on the ninth is to help one prepare for the impending fast on the tenth. The mitzva should be seen as an integral aspect of the fast itself, as the leadup to a successful fast. Rashi in Rosh Ha-shana (9b), however, appears to define the mitzva of eating on Erev Yom Kippur in absolute terms, regardless of the manner in which it facilitates the next day's fast. This question regarding the nature of the mitzva to eat on Erev Yom Kippur might impact several questions pertaining to its fulfillment.
R. Akiva Eiger (Responsa, 15) probes whether women are obligated to fulfill the mitzva of eating on Erev Yom Kippur. After all, since the mitzva is limited to the ninth of Tishrei, it might be defined as "zeman gerama" (time-bound), the type of mitzva from which women are excused. Alternatively, if the mitzva is part of the mitzva of fasting on the tenth and meant to prepare for that fast, we might obligate women in this mitzva, just as they are obligated in the fast itself.
Though the gemara itself does not mention this issue, an interesting gemara in Sukka (28) might influence our question. The gemara interprets the extra word "ha-ezrach" (Vayikra 16:29) as coming to include women in the obligation of tosefet Yom Kippur (the few minutes which we add to the actual fast). The gemara does not address the question of women being obligated to eat on the ninth. Is this because they are obligated even without an extra derivation, or because they are excused (as it is zeman gerama), and this exemption is indicated by the absence of a special verse to include them?
Commentators took varying stances regarding this gemara and the question of the obligation of women. The Yerushalmi (Ta'anit, end of ch. 2) relates that on the following days women are forbidden to fast: Shabbat, Yom Tov, Rosh Chodesh, Chanuka and Purim. As this list does not include erev Yom Kippur, it would appear that women are not formally obligated to eat on erev Yom Kippur.
A second question pertains to the obligation to eat during the night of the ninth. The Ran (Nedarim 63b) suggests that the mitzva applies both by night and by day, whereas it seems that Rashi (Ketuvot 5a) believes that the mitzva does not apply at night. Conceivably, this question stems from the nature of the mitzva. Assuming the mitzva is geared toward preparing us for the fast, we might not apply it at night, since food eaten at that point would not necessarily help one fast. If, however, we acknowledge the status of the ninth as a separate Yom Tov, the mitzva of eating might indeed begin the night before, akin to all other Yamim Tovim. In fact, many poskim suggested not saying Tachanun during Mincha of the eighth, since we never say Tachanun during Mincha preceding a Yom Tov beginning that night.
A third question pertains to whether a person must eat a formal meal including bread, or can simply eat whatever appeals to him. This question first raised by the Minchat Chinukh (mitzva 313) - might also be a product of our fundamental question. Assuming the mitzva serves only to prepare one for the fast, we might not insist on a meal beginning in ceremonial fashion with bread. If, however, we view the ninth as a separate Yom Tov, it MIGHT acquire all aspects of Yom Tov, including beginning a meal with bread.
May God grant you and all of Klal Yisrael a gemar chatima tova.