- אין לך טרפות אלא מה שמנו חכמים
The Gemara relates that דבי יוסף רישבא – the household of Yosef the Hunter would strike animals on the גיד הנשה to kill them. They came before Rebbe Yehudah ben Beseira to ask whether this act renders an animal a tereifah, and he replied:וכי להוסיף על הטרפות יש – is it possible to add to the list of known tereifos? אין לך אלא מה שמנו חכמים – You have no [טרפות] other than those the Sages enumerated! Similarly, the household of Rav Pappa bar Abba the Hunter used to strike animals in the kidney to kill them. They came before Rebbe Abba to ask whether this renders an animal a tereifah, and he gave an identical reply. The Gemara asks that we do see that animals die from these injuries (as evidenced by the practice of these hunters), and answers: גמירי דאי בדרי לה סמא חייא – we have a tradition that if they would spread medication on these injuries they would live, so the animals are not considered tereifos.
- בוקא דאטמא דשף מדוכתיה (dislocated thighbone)
The next Mishnah begins: ואלו כשרות בבהמה – these are the cases which are ruled kosher in animals, and proceeds to list numerous cases, some of which parallel those in the first Mishnah (with lesser defects). In the Gemara, Rebbe Yochanan says: אלו טרפות דוקא – the first Mishnah’s expression that “These are tereifah” is specific, intended to exclude a different case from being a tereifah. Reish Lakish says: אלו כשרות דוקא – this second Mishnah’s expression that “These are kosher” is specific, and intended to exclude a different case from being kosher. The Gemara explains that they argue about Rav Masna’s ruling: האי בוקא דאטמא דשף מדוכתיה טרפה – if the ball of the thighbone popped out of its place, it is a tereifah. Rebbe Yochanan says the Tanna is teaching that it is not a tereifah, and Reish Lakish says the Tanna is teaching that it is a tereifah. Rava says this case is permitted, but אי איפסיק ניביה טרפה – if its ligament was severed, it is a tereifah. The halachah is that it is kosher even if the ligament was severed, but if it was decayed, it is a tereifah.
- כאיסר כיתר מכאיסר (עד ולא עד בכלל)
The Mishnah taught that an animal remains kosher when the trachea is missing עד כאיסר האיטלקי – up to the size of an Italian issar. Rav Nachman says regarding this shiur, כאיסר כיתר מכאיסר – the size of an issar exactly is the same as more than an issar, and is a tereifah. The Gemara observes that Rav Nachman apparently holds עד ולא עד בכלל – that the term “until” used in Mishnayos means “up to but not including,” i.e., the Mishnah’s ruling that a missing trachea is kosher “until” the size of a כאיסר, that precise size is a tereifah. The Gemara challenges this contention from several Mishnayos and defends it, but eventually proves from Mishnayos discussing broken shards of כלים, which are tamei if the original כלי was “up to” a certain size, and that size itself is also tamei!? The Gemara on the next Daf will explain that in that case, saying "עד" is "בכלל" represents a חומרא (i.e., tumah), whereas in our case of a deficient trachea, saying "עד" (a כאיסר) is not "בכלל" represents a חומרא (i.e., a tereifah), and the Mishnah is always interpreted stringently. As Rebbe Yochanan said: כל שיעורי חכמים להחמיר – all the measures taught by the Sages are interpreted stringently (except for bloodstains for a possible נדה).