In our previous two installments, we discussed the obligation of peter chamor, which requires “redeeming” a firstborn donkey, noting that whereas the Torah (Shemot 13:13) commands redeeming the donkey with a sheep, the Gemara (Bekhorot 11a) teaches that it may be done also through other means. The Gemara explains that one fulfills this mitzva by giving a sheep to a kohen even if its value is far less than the donkey’s, but one can also redeem the donkey with money or objects of value equivalent to the donkey’s value. As we saw, the Beit Yosef (Y.D. 321) inferred from the formulation of the Rambam (Hilkhot Bikkurim 12:11) that the option of using money or objects of value is available only as a last resort, if one does not have a sheep with which to redeem the donkey.
The question naturally arises as to why this should be the case. What exactly is the relationship between these two options – the preferred option of redeeming the firstborn donkey with a sheep, and the second option of using money or other objects of value? Yesterday, we explored the possibility that in truth, one fulfills the mitzva of peter chamor only with a sheep, and the Gemara meant only that if one does not have a sheep, he should redeem the donkey through money to divest it of its status of sanctity so it becomes permissible for use. According to this view, the mitzva of peter chamor actually requires using a sheep – as the straightforward reading of the verse suggests – but one who cannot fulfill the mitzva should redeem the donkey through other means so it does not remain forbidden for use.
Some, however, suggested a much different approach to explain the Rambam’s position, based on the comments of the Ritva in a separate context. The Torah in Sefer Devarim (25:5-10) introduces the yibum obligation, requiring the brother of a married man who died without children to marry the widow, or to perform the chalitza ceremony to release the widow from the levirate bond. In describing the chalitza ceremony, the Torah instructs that the widow must remove “na’alo” – “his shoe” – from the brother’s foot (Devarim 25:9). The plain meaning of the verse is that the shoe which the widow removes should be the brother’s shoe, but the Gemara in Masekhet Yevamot (103b) derives from the next verse (“chalutz ha-na’al”) that in truth, even somebody else’s shoe may be used for this purpose. The word “na’alo,” the Gemara explains, is used to instruct that the shoe must be the proper size to fit the brother’s foot, but it does not have to belong to him. Nevertheless, the Gemara later establishes that although the chalitza is effective if somebody else’s shoe is used, preferably, a shoe belonging to the deceased’s brother should be used.
The Rishonim debate the question as to why this is the case. The Rashba speculates that Chazal may have enacted this provision as a way of ensuring that the shoe would fit the brother’s foot. If the brother wears somebody else’s shoe, it might not be his size, in which case the chalitza is invalid. In order to avoid this mistake, Chazal instituted using the brother’s own shoe – which can, quite obviously, be presumed to be his foot’s size – for chalitza.
The Ritva, however, writes that Chazal established this provision “le-kayeim peshuto shel mikra” – in order to uphold the straightforward reading of the verse. Intriguingly, the Ritva asserts that the Sages saw fit to require acting in accordance with the plain meaning of the verse, even though halakhic exegesis has shown that the act may be done differently. Even after it was determined that anybody’s shoe may be used for chalitza, Chazal established that the brother’s shoe should be used, in order to fulfill the requirement as indicated by “peshuto shel mikra.”
It has thus been suggested that the Rambam’s understanding of the peter chamor requirement may perhaps be understood along similar lines. Although Chazal determined that one fulfills the mitzva through any object of value, and not just a sheep, the plain meaning of the verse is that specifically a sheep must be used for this purpose. Therefore, according to the line of reasoning expressed by the Ritva in regard to chalitza, it follows that there should be a rabbinic requirement to redeem a firstborn donkey specifically with a sheep. And it is perhaps for this reason, then, that the Rambam indicates that other means of redeeming are allowed only if one is unable to redeem the donkey with a sheep.