But according to the one who says: There is a source for the slaughter of a bird in the Torah, there is disqualification for ripping simanim in a bird as well.

Rav Ashi said to him: On the contrary, the opposite is reasonable. According to the one who says: There is a source for the slaughter of a bird in the Torah, the halakhot of slaughter are not explicit and were transmitted to Moses orally, and it can be said that this is what God taught him, that there is no disqualification for ripping simanim. And even according to the one who says that the halakhic status of a bird is like that of an animal, as the halakhot of the slaughter of a bird are derived from the halakhot of the slaughter of an animal, perhaps God taught Moses that with regard to the matter of ripping simanim it will not be like an animal.

But according to the one who says: There is no source for the slaughter of a bird in the Torah, but rather it is by rabbinic law, from where are the halakhot of the slaughter of a bird learned? They are learned from the halakhot of the slaughter of an animal; consequently, the entire matter of the slaughter of a bird is like that of an animal.

Ravina said: Ravin bar Kisi said to me: With regard to that which Rami bar Yeḥezkel teaches, i.e., that there is no disqualification for ripping simanim in a bird, we say it only with regard to pinching, but with regard to slaughter, there is disqualification for ripping simanim. The Gemara objects: But doesn’t Rabbi Yirmeya say that Shmuel says: Any place that is valid for slaughter on the throat is correspondingly valid for pinching on the nape, but that which is not valid for slaughter is not valid for pinching. The Gemara explains: That halakha disagrees with this statement of Shmuel.

§ Ze’eiri says: If the neck bone of an animal or a bird was broken and most of the surrounding flesh was cut with it, the status of the animal or the bird is that of an unslaughtered carcass. It is dead and can no longer be rendered fit by slaughter.

Rav Ḥisda said that we learn this in a mishna (Zevaḥim 68a) as well: If one pinched a bird offering with a knife and not with his thumbnail, the bird renders the garments of one who swallows it impure when it is in the throat, which is the halakha in the case of an unslaughtered carcass of a kosher bird. And if you would say that if the neck bone of an animal or a bird was broken and most of the surrounding flesh was cut with it, the bird is not an unslaughtered carcass but it is a tereifa, then since with regard to a bird offering its pinching is its slaughter, let pinching with a knife be effective to purify the bird from the impurity of an unslaughtered carcass, as a tereifa does not transmit impurity when slaughtered properly. From the halakha that pinching with a knife does not render the bird pure it is evident that when its neck bone is broken the bird is rendered an unslaughtered carcass.

The Sages say in response: There, pinching with a knife is ineffective in rendering it pure not because the breaking of the neck bone renders the bird an unslaughtered carcass. Rather, it is because it is not slaughter at all. The Gemara asks: What is the reason? Rav Huna says: It is because he conceals the knife and performs an inverted slaughter, which invalidates the slaughter. Rava says: It is because he presses the knife.

The Gemara asks: With regard to the one who says: Because he conceals the knife and performs an inverted slaughter, what is the reason that he does not say: Because he presses the knife? The Gemara answers: It is because he holds that drawing back and forth in pinching is valid. The Gemara asks: And the one who says: Because he presses the knife, what is the reason that he does not say: Because he conceals [maḥlid] the knife? The Gemara answers that he could have said to you: What are the circumstances of concealing the knife? It is like a rat [ḥulda] that resides in the foundations of houses that are concealed. Here, when he begins cutting from the nape of the neck, that knife is exposed.

Rava said: If that which Ze’eiri said: If the neck bone of an animal or a bird was broken and most of the surrounding flesh was cut with it, the status of the animal or the bird is that of an unslaughtered carcass, is difficult for me, this is difficult for me: How does pinching a bird offering prepare it for sacrifice? Since pinching involves breaking the neck bone and cutting most of the surrounding flesh with it before cutting the simanim, what significance is there to pinching the simanim? And does he stand and pinch a dead bird? If it is dead, of what use is the pinching?

Abaye said to him: And even without the statement of Ze’eiri, let the case of a bird burnt offering be difficult for you, as it requires cutting of two simanim. Since slaughter of a non-sacred bird requires cutting of one siman, once one siman is cut the bird is considered dead for all intents and purposes, and does he stand and pinch a dead bird? Rava said to him: There, he continues pinching in order to fulfill through it the mitzva of separation between the head and the body in the bird burnt offering.

The Gemara asks: If so, there should be an obligation to cut the skin of the bird as well in order to fulfill the mitzva of separation. Abaye answers: Any element that invalidates slaughter invalidates separation, and any element that does not invalidate slaughter does not invalidate separation. Failure to cut the skin does not invalidate slaughter.

The Gemara objects: But isn’t there the minority of the simanim according to the Rabbis, which do not invalidate slaughter, as, if one slaughtered a majority of the simanim and a minority remained uncut, the slaughter is valid, and they hold that they invalidate separation? The Gemara clarifies: Rather, say: Any element that is in effect with regard to slaughter is in effect with regard to separation, and any element that is not in effect with regard to slaughter is not in effect with regard to separation. The two simanim, although they do not invalidate slaughter, are part of the mitzva of slaughter, while the skin is not part of the mitzva of slaughter.