Bekhorot 10 - September 28, 17 Tishrei

Even though Rabbi Shimon and Rabbi Yehuda disagree regarding whether a firstborn donkey (peter chamor) is forbidden for benefit, Rabba maintains that Rabbi Shimon, who permits benefit prior to redemption, agrees that if the donkey was not redeemed and its neck was broken, it becomes forbidden for benefit. Rabba derives this law via a gezeira shava comparing the term "breaking the neck" (arifah) used here to that of an egla arufa, which is forbidden for benefit once its neck is broken.

Rabba attempts to prove his assertion from a braita concerning a dispute between the rabbis and Rabbi Shimon over several items regarding susceptibility to food impurity, including a firstborn donkey. In that braita, Rabbi Shimon holds it is not susceptible to food impurity, which Rabba infers as evidence that it is forbidden for benefit after its neck is broken. However, Rabba’s proof is rejected after two alternative explanations for the core debate in the braita are proposed, though ultimately both alternative interpretations are refuted as well. A further challenge is raised against Rabba from another braita, but this difficulty is successfully resolved.

Rav Huna supported Rabba’s ruling and cited two braitot to demonstrate that Rabbi Shimon considers the firstborn donkey forbidden for benefit after its neck is broken, yet both proofs are shown to be inconclusive. The Gemara then introduces a different version regarding how Rav Nachman’s opinion was framed, connecting it directly to a Mishna that discusses betrothing a woman with a firstborn donkey. An alternative version of the sugya pertaining to that Mishna is presented as well.

The opinion of Rabbi Yochanan (and some say Rabbi Elazar) is brought: he disagrees with Rabba and Rav Huna, holding that according to Rabbi Shimon, the donkey remains permitted for benefit even after its neck has been broken. Resh Lakish, however, agrees with the position of Rabba and Rav Huna.