Bekhorot 4

The Mishna rules that Kohanim and Levites are exempt from bekhora (firstborn male donkeys) based on a kal v’chomer: if they exempted the firstborns of Israelites in the desert, logic dictates that they exempt their own.

The Gemara challenges the Mishna’s premise as the Levites themselves did not exempt the donkeys of the Israelites – they themselves exempted the Israelite firstborn males, and their animals exempted the Israelite firstborn donkeys. Two answers are offered to resolve this question, by both Abaye and Rava. Abaye answers that the Mishna means the livestock of the Levites exempted their own livestock. Rava rejects Abaye’s interpretation on two grounds: first, the Mishna uses the verb “they exempted”, referring to the Levites themselves; second, if Abaye were correct, Levites’ kosher firstborn animals should be exempt from bekhora also, yet a Mishna explicitly teaches that Kohanim and Levites are obligated in the firstborn of kosher animals and exempt only from redeeming their sons (pidyon haben) and firstborn donkey (peter chamor). Rava provides his own answer, explaining that the Levites exempted themselves (their human firstborns) via kal v’chomer from what transpired in the desert where the Levites exempted the Israelite firstborns. To derive their exemption from the firstborn donkey (peter chamor), the Gemara cites a verse equating human firstborns with impure animal firstborns (“האדם ואת בכור הבהמה הטמאה תפדה”), establishing that whoever is exempt from human firstborn is exempt from the redemption of the donkeys.

Rav Safra raises four difficulties against both Abaye and Rava: if the exemption depends on the Levites’ exchange in the desert, what about those who were not involved in the exemption, such as a Levite who did not own animals or was under a month old, or a female Levite, or Aharon? All difficulties are resolved. Three other questions are asked and answered, namely, the source for kohanim being included in this exemption, that this exemption applies for future generations, and that the redemption of a firstborn donkey in the desert was performed specifically with a lamb (seh) just as it is for future generations.

Rav Chanina states that a single lamb belonging to a Levite exempted multiple firstborn donkeys of Israelites in the desert. Abaye attempts to prove this from the fact that Scripture notes how many excess human firstborns there were compared to Levites, but did not mention any excess firstborn animals. After rejecting Abaye’s proof, the Gemara proves this from the precise phrasing “ואת בהמת הלוים תחת בהמתם” – “an animal (single) of the Levites in place of their (Israelites) animals (plural)”, and Rava notes that this aligns with a Mishna ruling that one may redeem with a lamb multiple times, and the Gemara explains that Rabbi Chanina’s statement was meant to give the reason for that Mishna.

There is a dispute between Rabbi Yochanan and Reish Lakish regarding whether firstborns were sanctified in the desert. Rabbi Yochanan argues they were sanctified as can be seen in the verse in Shmot 13:2 (“קדש לי כל בכור” – “sanctify to me all the firstborn”), while Reish Lakish argues they were not sanctified until entering the Land as in the verse Shmot 13:12 (“והיו כי יביאך… והעברת” – “and when God will bring you into the land… you shall set apart all firstborn”). Rabbi Yochanan challenges Reish Lakish from two tannaitic sources, but both difficulties against Reish Lakish are resolved. An alternative version suggests that the second difficulty was brought by Reish Lakish to raise a difficulty with Rabbi Yochanan’s position. A third source is brought by the Gemara to prove Rabbi Yochanan’s position, but Rav Nachman bar Yitzchak provides an alternative explanation of the source to fit with Reish Lakish.