But in the case of one who vows and says: It is incumbent upon me to bring an offering, even Rabbi Yehuda concedes that no, it is best not to vow at all. Likewise, it is preferable not to vow to donate a certain monetary value to the Temple treasury. Apparently, then, the statements in that mishna: Everyone takes vows of valuation, and: Everyone vows to donate the assessment of a person to the Temple treasury, do not indicate that it is permitted to do so ab initio.

Rav Ashi responded: And is that to say that every use of the term: Everyone, is an indication that the action in question is not permitted ab initio? Rather, is the term: Everyone, in the baraita that states: Everyone is obligated in the mitzva of sukka, and in the baraita that states: Everyone is obligated in the mitzva of ritual fringes, also an indication that they are not permitted ab initio?

Rav Aḥa answered: I am not speaking about cases where it is stated: Everyone is obligated, as it goes without saying that fulfilling any obligation is permitted ab initio. Rav Ashi asked: If that is so, that which was stated: Everyone who brings an offering places hands on the animal, both men and women (see Menaḥot 93a), is that also an expression indicating that it is not permitted ab initio? But isn’t it written: “And he shall place his hand upon the head of the burnt offering, and it shall be accepted for him to effect atonement for him” (Leviticus 1:4)?

Rav Aḥa answered: Indeed, there are instances where the word: Everyone, indicates ab initio, and there are instances where the word: Everyone, indicates after the fact. Rather, concerning the term: Everyone, that appears here in the mishna, from where can it be determined that it is an expression indicating that it is permitted ab initio, creating an apparent contradiction in the mishna that will be difficult for you? Perhaps it is an expression indicating that everyone’s slaughter is valid after the fact, and there will not be a contradiction in the mishna that will be difficult for you.

Rav Ashi said to Rav Aḥa: I find the phrase: And their slaughter is valid, to be difficult for me. From the fact that the tanna teaches: And their slaughter is valid, which is an expression indicating that it is valid after the fact, conclude by inference that the initial phrase in the mishna: Everyone slaughters, is an expression indicating that it is permitted ab initio. As, if it indicated that it is valid after the fact, why do I need two phrases teaching that it is valid after the fact?

Rabba bar Ulla said, in resolution of the conflict in the mishna, that this is what the mishna is teaching: Everyone slaughters, and even a ritually impure person may slaughter a non-sacred animal ab initio. The Gemara interjects: What is the purpose of stating that a ritually impure person may slaughter a non-sacred animal ab initio? There is no prohibition against rendering non-sacred meat impure. The Gemara answers that the reference is to non-sacred animals that were being prepared according to the strictures of sacrificial food, and the tanna holds that the halakhic status of non-sacred foods that were prepared according to the strictures of sacrificial food is like that of sacrificial food insofar as it is prohibited to render such food impure.

The Gemara asks: How does an impure person act in order to ensure that he will not render the flesh of the slaughtered animal impure? The Gemara answers: He brings a long knife and slaughters the animal with it, so that he will not come into contact with the flesh of the slaughtered animal.

Rabba bar Ulla continues his interpretation of the mishna: And the reason the mishna also indicates that he may not slaughter ab initio is that with regard to sacrificial animals, he may not slaughter them ab initio even with a long knife, lest he come into contact with the flesh. But if he slaughtered the sacrificial animal and says: It is clear to me that I did not come into contact with the flesh, his slaughter is valid after the fact.

And it teaches: This is the halakha with regard to all people except for a deaf-mute, an imbecile, and a minor, who, even if they slaughtered only non-sacred animals, their slaughter is not valid even after the fact. The reason the Sages deemed such slaughter not valid is lest people in these categories interrupt the slaughter, lest they press the knife in the course of slaughter, and lest they conceal the knife beneath the windpipe or the gullet in the course of an inverted slaughter.

The Gemara asks: If so, with regard to the clause that follows in the mishna: And any of them who slaughtered an animal and others see and supervise them, their slaughter is valid, to which case in the mishna is it referring? If we say that the reference is to the case of a deaf-mute, an imbecile, and a minor, why was it formulated: And any of them who slaughtered? Since it stands adjacent to that halakha, the tanna should have formulated the phrase: And if they slaughtered. Rather, perhaps the reference is to the case of a ritually impure person who slaughtered a non-sacred animal. The Gemara rejects that possibility as well. But didn’t you say in that case: He slaughters the animal even ab initio?

And rather, perhaps the reference is to the case of a ritually impure person who slaughtered a sacrificial animal. The Gemara rejects that possibility, as in that case, if the ritually impure person says: It is clear to me that I did not come into contact with the flesh, it is sufficient, and there is no need for supervision. The Gemara answers: Supervision is necessary in the case of a ritually impure person who slaughtered a sacrificial animal, to account for a case where the ritually impure person is not before us so that we can ask him whether he came into contact with the flesh.

The Gemara asks: Is this halakha of a ritually impure person who slaughtered a sacrificial animal learned from an analysis of the mishna here? It is learned explicitly from the mishna there (Zevaḥim 31b): With regard to all those who are unfit for Temple service who slaughtered an offering, their slaughter is valid, as the slaughter of an offering is valid ab initio when performed even by non-priests, by women, by Canaanite slaves, and by ritually impure individuals. And this is the halakha even with regard to offerings of the most sacred order, provided that the ritually impure will not touch the flesh of the slaughtered animal, thereby rendering it impure.

The Gemara answers: The mishna here is the primary source. There, since the tanna taught the rest of those disqualified for Temple service, he taught the case of a ritually impure person who slaughtered a sacrificial animal as well. And if you wish, say instead that the mishna there is the primary source, as it is standing in tractate Zevaḥim, which deals with sacrificial animals. Here, since the tanna taught the case of a ritually impure person who slaughtered a non-sacred animal, he also teaches the case of a ritually impure person who slaughtered a sacrificial animal.

The Gemara asks: This ritually impure person mentioned in the mishna is one who became impure with what form of impurity? If we say that he became impure with impurity imparted by a corpse, this is difficult, as the Merciful One states: “And whosoever in the open field touches one slain with a sword” (Numbers 19:16).