- Shechting רוב of a סימן applies equally to חולין and קדשים
The Mishnah on Daf 27a stated twice that shechting most of one סימן of a bird, and most of two סימנים in an animal, is a valid shechitah. Rav Hoshaya explains that one clause refers to animals which are chullin, and the other refers to kodashim (i.e., korbanos). Both are necessary, for had the Mishnah only taught the law of chullin, one might think that most of a סימן only suffices for chullin, because he has no need for the animal’s blood, but regarding kodashim, דלדם הוא צריך – where he needs the blood for זריקה on the מזבח, perhaps shechting most of the סימן is insufficient. Had the Mishnah only taught kodashim, one might think that shechting רוב of the סימן is only necessary for kodashim, since the blood is needed, but for chullin, perhaps shechting half would suffice. Therefore, the Mishnah taught that shechting most of the סימן applies to both. Amoraim say that the Mishnah’s first clause refers to kodashim, and the second clause refers to chullin, based on five different proofs.
- Machlokes if ישנה לשחיטה מתחלה ועד סוף
Reish Lakish quoted Levi the Elder saying: אינה לשחיטה אלא בסוף - shechitah is only [considered shechitah] at the end of the procedure. Rebbe Yochanan says: ישנה לשחיטה מתחילה ועד סוף – shechitah is [considered shechitah] from beginning to end. Rava clarifies that where a non-Jew shechted one סימן and a Jew shechted the second סימן, all agree the shechitah is invalid, since the עכו"ם already made it a טריפה. Similarly, if one performs melikah of one סימן of an עולת העוף below the חוט הסיקרא and the other above it, all agree it is invalid, since he performed a full melikah procedure of a חטאת העוף below. Rava says they argue where one shechted one סימן of a bird korban outside the Mikdash, and the other סימן inside the Mikdash. However, Rav Yosef said that in this case, all agree one is חייב for shechting a korban outside the Mikdash, since he performed a full melikah of a חטאת העוף outside. Therefore, the Gemara concludes that they argue where one shechted a minority of the סימנים outside the Mikdash, and completed the shechitah inside. Rebbe Yochanan considers the entire procedure part of the shechitah, and he is liable for shechting בחוץ, and Levi the Elder holds he is exempt, because it is only considered shechitah at the end, which was inside the Mikdash.
- Which people involved in a disqualified פרה אדומה become tamei?
Rebbe Yochanan is challenged from a Mishnah: כל העסוקין בפרה מתחלה ועד סוף – all those involved in the procedure of the parah [adumah], from beginning to end, are מטמא their clothing (and bodies), and can disqualify the פרה אדומה by performing another task simultaneously. If the פרה became invalidated during the shechitah, then someone involved is not מטמא his clothing, whether he was involved before or after it was invalidated, because he was not involved with a legitimate "פרה אדומה". However, if the פרה became disqualified during the הזאה – sprinkling of its blood, then someone involved before the invalidation is מטמא his clothing (since it was a properly shechted פרה אדומה), but someone involved after the invalidation is not מטמא his clothing. According to Rebbe Yochanan, who considers every part of the shechitah as shechitah, the same distinction should apply to invalidated shechitah, that someone involved before the invalidation should be מטמא his clothing!? Rava replied that a ruined shechitah is different, דאגלאי מלתא למפרע דלאו שחיטה היא כלל – because it is retroactively revealed that [the initial cutting] was not actually shechitah at all.