Chullin Daf 93 צולין דַף 93

Shmuel says: חלב שהבשר חופה אותו מותר – the section of cheilev (of the flanks) which is covered by meat is permitted, because the passuk only prohibits cheilev שעל הכסלים – which is on (the surface of) the flanks, ולא שבתוך הכסלים – but not the חלב which is in the flanks. The Gemara objects that Shmuel himself ruled that the fats beneath the loins are prohibited, even though they are covered by meat!? Abaye answered: בהמה בחייה פרוקי מיפרקא – while an animal is alive, [its limbs] separate from each other as it walks, periodically exposing that fat. Rebbe Yochanan also said, “I am neither a butcher nor the son of a butcher, but I recall that they would say this in the בית מדרש: while an animal is alive, its limbs separate from each other, leaving חלב uncovered.

The Gemara states: טבח שנמצא חלב אחריו – concerning a butcher after whom cheilev was found (i.e., sold meat without fulfilling his responsibility to remove all the חלב), Rav Yehudah says he is punished בכשעורה – if the meat contained a mere barleycorn’s volume of חלב. Rebbe Yochanan requires a כזית of חלב. Rav Pappa says they do not argue: Rebbe Yochanan’s measure of a כזית is להלקותו – to give him lashes (a Rabbinic punishment for causing others to sin), whereas Rav Yehudah’s smaller measure of a כשעורה is לעברו – to remove him from being allowed to sell meat. Mar Zutra says that the measure of a כשעורה applies to חלב found in one place, while the measure of a כזית applies to חלב found in two or three places. The halachah is that the measure for lashes is a כזית, and a כשעורה warrants removing a butcher from his position.

In the Mishnah on Daf 89b, Rebbe Meir said that butchers are not trusted to remove the entire גיד הנשה, but the Chochomim say they are trusted. Rebbe Yochanan says חזרו לומר נאמנין – they later reversed their ruling to say that [butchers] are trusted. This implies they initially were not trusted, and Rav Nachman asks: אכשור דרי – have the generations improved, that the butchers have become more trustworthy?! The Gemara explains that initially, they ruled like Rebbe Meir, that removing the גיד הנשה requires “digging after it” and removing even embedded offshoots (as presented on the previous Daf), and butchers could not be trusted to carry out this painstaking task. Later, they retracted and ruled like Rebbe Yehudah, who only required removing the surface section of the גיד הנשה, and butchers could be relied upon to do so.