Bekhorot 17 - October 5, 24 Tishrei

The Gemara continues to analyze the dispute between Rav Huna and Rav Yehuda regarding the offspring generations of guaranteed livestock (tzon barzel) that one received from a non-Jew. It evaluates their views against the ruling of Rabban Shimon ben Gamliel in the Mishna and against the statement of the tanna kamma in the first clause (reisha) of the Mishna, demonstrating how each Amora reinterprets the words of both Rabban Shimon ben Gamliel and the tanna kamma. Regarding a ewe that gives birth to a goat-like species or a goat that gives birth to a sheep-like species (nidmeh), a braita brought by Rav Oshaya from Nehardea records that Rabbi Meir obligates the offspring while the Sages exempt it. The Gemara clarifies the subject of their dispute. After rejecting the possibilities that it concerns firstborn status (bekhorah), first shearings (reishit hagez), or slaughtering a mother and child on the same day (oto veet beno), the Gemara returns to state that it indeed concerns firstborn status, but under special circumstances—presenting three options to explain the specific case in which they disagree and the precise point of dispute. Rabbi Yochanan notes that Rabbi Meir agrees that the Rosh Chodesh goat offering (se'ir shel rosh chodesh) must come from a female goat born to a goat and not from a hybrid offspring (nidmeh). An objection is raised against him: no sacrifice may come from a nidmeh, as derived from an explicit exposition! To resolve this, the Gemara explains that both verse derivations are necessary. The Gemara discusses the status of wool that came from a nidmeh (such as a ewe born to a goat). Such wool is exempt from the prohibition of mixed species (kilayim/ shaatnez), invalid for tekhelet threads in tzitzit, and immune to garment leprosy (nega'im), as derived by an analogy to flax (pishtan), which cannot have a nidmeh counterpart. Similarly, Rav Ashi rules that wine from a vine draped over a fig tree is invalid for altar libations (nesakhim). The Mishna addresses a ewe that gives birth to two male lambs whose heads emerge simultaneously. Rabbi Yosi HaGelili holds both go to the kohen based on the plural verse "the males belong to Hashem", whereas the Sages hold exact simultaneity is impossible (i efshar letzamtzem), so one belongs to the owner and one to the kohen. Rabbi Tarfon lets the kohen choose the better lamb, while Rabbi Akiva rules that the kohen receives the leaner one, with the second lamb grazing until it contracts a blemish; it remains liable for priestly gifts (matanot), whereas Rabbi Yosi exempts it. If one lamb dies, Rabbi Akiva rules that the burden of proof rests on the claimant (hamotzi mechavero alav hare'aya) and the animal remains with the owner. In analyzing the principle of simultaneity/exactness (tzimtzum), the school of Rav Yannai asks whether human precision (beyedei adam) is possible according to the Sages, even if exact simultaneity at birth is impossible. They bring four examples—the red line on the Altar (chut hasikra), the dimensions of Sanctuary vessels, impurity in equal halves of a broken earthenware vessel, and a corpse found equidistant between two cities—to reach a conclusion, but each possibility is rejected.