Chullin 18 - May 18, 2 Sivan

Slaughterers who failed to show their knives to a Chacham (Sage) for inspection were penalized, though the severity of the penalty differed depending on whether the knife was subsequently found to be smooth or notched. The teeth of a harvest sickle incline in one direction; therefore, if one used it to slaughter in the direction that cuts cleanly without tearing, Beit Shammai and Beit Hillel dispute its validity. However, Rabbi Yochanan clarifies that both agree the slaughter is invalid, and their actual debate is whether the animal is classified as a neveila (a carcass, which imparts impurity) or a treifa. The windpipe features a large ring at the top that encircles it entirely, unlike the lower rings which are C-shaped and do not completely cover it. The Mishna presents two opinions regarding the highest anatomical point where slaughter can be performed without being disqualified by hagrama (slanting outside the designated slaughter area). The Tanna Kama rules that the large ring must be completely severed while leaving a width of a thread of the top ring untouched. Conversely, Rabbi Yossi b'Rabbi Yehuda rules that as long as the majority of the windpipe is cut in the valid area, the slaughter is kosher, even if the slaughterer subsequently cuts above it into the area known as "the hat" (kova) - since the act was legally complete once the majority was cut. Rav and Shmuel explain that Rabbi Yossi b'Rabbi Yehuda also forbade slaughtering directly on the smaller rings, permitting it only between them since they do not encircle the entire windpipe. However, after challenging this with a contradictory braita where Rabbi Yossi b'Rabbi Yehuda explicitly permits slaughtering on the smaller rings, the Gemara concludes that Rav and Shmuel agreed with his view regarding the large ring but ruled against his lenient stance on the smaller rings. When Rabbi Zeira moved from Babylonia to Israel and permitted slaughtering on these rings, the Sages questioned why he did not maintain the stringencies of Rav and Shmuel, given the halakhic rule that a traveler must observe the stringencies of both their place of origin and their destination. Two resolutions are suggested, each presenting different exceptions to the rules of local custom. Ultimately, the Gemara notes that customs varied across different regions of Babylonia, and not all areas adopted this stringency. There is a dispute between Rav Papi and Rav Papa regarding the exact anatomical boundary for the highest point of the windpipe where shechita remains valid.