Chullin Daf 20 צולין דַף 20

Rebbe Chiya’s sons ruled that melikah may be performed by moving the סימנים around to the back of the neck. The Gemara objects that our Mishnah states that “what is valid for shechitah is not valid for melikah,” which presumably comes to teach that this case is not valid!? Rebbe Yirmiyah answers that the Mishnah means למעוטי מוליך ומביא – to exclude [melikah performed with] moving his nail back and forth, instead of cutting straight down into the bird’s neck. The Gemara asks that this answer fits according to the opinion that "מוליך ומביא" is indeed פסול for melikah, but not according to the opinion that it is valid!? It answers that Rebbe Chiya’s sons hold that מוליך ומביא is invalid for melikah. Rav Kahana said: מצות מליקה קוצץ ויורד – the mitzvah of melikah is that one cuts the bird’s neck and goes straight down until cutting a סימן, וזו היא מצותה – and this is its mitzvah. Rebbe Avin thought to infer that only cutting straight down is valid, but מוליך ומביא would not be valid. However, Rebbe Yirmiyah told him: כ"ש דמוליך ומביא במליקה כשר – all the more so that moving back and forth is valid for melikah! Rather, Rav Kahana meant: אף זו היא מצותה – even this method is its mitzvah.

Rami bar Yechezkel taught a Baraisa: אין עיקור סימנין בעוף – the disqualification of torn pipes (i.e., סימנים which are dislocated before shechitah) does not apply to a bird. Rav Acha brei d’Rava told Rav Ashi that this is only true according to the opinion that אין שחיטה לעוף מן התורה – there is no requirement of shechitah for a bird from the Torah (and it is only required מדרבנן), but according to the opinion that birds requires shechitah מדאורייתא, the disqualification of dislocated סימנים would apply to them as well. Rav Ashi replied that the opposite is more logical: if shechitah is required מדאורייתא, it is possible דהכי אגמריה דאין עיקור – that [Hashem] taught [Moshe] this exception, that עיקור סימנים does not apply to shechitah of birds. But if birds only require shechitah מדרבנן, it was modeled after the Biblically required shechitah of animals, so dislocated סימנים should likewise be invalid. Ravin bar Kisi told Ravina that the exclusion of birds from עיקור סימנים only applies to melikah, but regarding shechitah, birds are also disqualified. However, the Gemara notes that Shmuel, who implied that anything which is פסול for shechitah is also פסול for melikah, argues with this distinction.

Zeiri said: נשברה מפרקת ורוב בשר עמה – if [an animal’s] neck bone is broken along with most of the flesh on it, it is immediately a נבילה, not merely a טריפה (therefore, it can convey tumah even while it is still moving, and shechting it would not prevent it from being metamei). Rav Chisda presents a Mishnah which appears to support this ruling, because it states that if one performs melikah with a knife, the bird is metamei like a נבילה. Amoraim give different explanations for this ruling. Rav Huna says: מפני שהוא מחליד – because [the שוחט] burrows the knife under the neck bone (which does not separate after being cut, like the neck does during shechitah). Rava says: מפני שהוא דורס – because [the שוחט] presses the knife down without moving it back and forth. Rav Huna did not give this explanation, because he holds מוליך ומביא is valid for melikah, so the above Mishnah’s ruling includes a case of cutting back and forth, not just pressing down. Rava did not give Rav Huna’s explanation, because he defines "חלדה" as where the knife is כחולדה הדרה בעיקרי בתים דמכסיא – like a weasel living under houses, which is completely hidden, but in this case, הא מיגליא – [the knife] is exposed during the entire shechitah.