Talmud - Nedarim 13a נדרים י״ג א׳

that he places the meat of a firstborn animal in one place and he places another piece of meat next to it, and he said: This second piece of meat is hereby like that meat of the firstborn animal, and it is a dispute between tanna’im about whether he is referring to the original forbidden status of the firstborn animal or its current permitted status?

The Gemara responds: No, everyone agrees that he is referring to the status of the animal before the sprinkling of the blood, and what is the reason of the one who renders it permitted? The verse states: “When a man takes a vow” (Numbers 30:3), which indicates that he has not done so until he takes a vow with an item forbidden by means of a vow, i.e., by extending the status of an item that itself was forbidden by a means of a vow. This comes to exclude a firstborn, which is an item that is forbidden by the Torah rather than by means of a vow; a firstborn animal is sacred simply because it is born first.

And the one who renders it forbidden holds that it is because the verse states: “To the Lord” (Numbers 30:3), which comes to include one who takes a vow by associating an object with an item that is forbidden by the Torah.

The Gemara asks: And the one who renders it permitted based on the principle that one cannot take a vow by associating the item with an item that is forbidden by the Torah, what does he do with the expression “to the Lord”? The Gemara answers: He requires this expression to include the case of one who associates the object of his vow with a sin-offering and a guilt-offering. Although these offerings are obligatory rather than voluntary, and in that regard they are dissimilar to items forbidden by means of a vow, one can render another item forbidden by associating it with these offerings.

The Gemara asks: And what did you see that led you to include a sin-offering and a guilt-offering and to exclude the firstborn? The Gemara answers: I include the sin-offering and guilt-offering due to the fact that he associates the object of his vow with an animal forbidden by means of a vow, as it is the individual who designates a particular animal for one of these offerings. And I remove the firstborn, because it is sacred from its mother’s womb.

And the one who renders it forbidden is of the opinion that one who says that a piece of meat shall be considered for him like the meat of a firstborn also associates the object of his vow with an item forbidden by a vow, as it is taught in a baraita: They said in the name of Rabbi Yehuda HaNasi: From where is it derived that if one has a firstborn animal born in his home it is still a mitzva to consecrate it? As it is stated: “The males you shall consecrate” (Deuteronomy 15:19). Although a firstborn animal is considered consecrated from birth, its owner is still commanded to declare it consecrated, and it is therefore considered an item forbidden by means of a vow.

And the one who renders it permitted in this case argues that although the owner is required to declare it consecrated, if he does not consecrate it, is it not consecrated? Since it is consecrated in any event, it is considered to have been rendered forbidden by the Torah rather than through a vow.

§ It is taught in the mishna that if one says that food shall be considered like the lamb [imra] of the daily offering, or like the animals designated as offerings and kept in special enclosures, the vow takes effect.

It was taught in a baraita: If one says that food shall be considered a lamb, for a lamb, like a lamb; enclosures, for enclosures, like enclosures; wood, for wood, like wood; fires, for fires, like fires; the altar, for the altar, like the altar; the Sanctuary, for the Sanctuary, like the Sanctuary; Jerusalem, for Jerusalem, like Jerusalem; with regard to all of them, if he adds: That which I will eat of yours, it is forbidden. This is because his intent is that whatever he eats that belongs to the other individual should be forbidden to him like one of these consecrated items. However, if he adds: That which I will not eat of yours, the food is permitted, since the only implication of his statement is that whatever he does not eat shall be forbidden.

The Gemara asks: Who is the Sage of whom we have heard, for whom there is no difference whether one said a lamb, for a lamb, or like a lamb, that I eat of yours? It is Rabbi Meir. Conversely, Rabbi Yehuda holds that the vow takes effect only if one says: Like a lamb.

However, say the latter clause of the baraita: With regard to all of them, if he adds: That which I will not eat of yours, the food remains permitted. But didn’t we learn in the next mishna that if one says: That which I will not eat of yours shall be for an offering [lekorban], Rabbi Meir prohibits him from eating food belonging to the other individual? And Rabbi Abba said in explanation of this ruling that it is as though he said: It shall be for an offering [lekorban], and therefore I will not eat that which is yours. Apparently, according to Rabbi Meir the food is forbidden even if he said: That which I will not eat of yours.

The Gemara responds: This is not difficult: This baraita is referring to a case where one said: That which I do not eat from you shall not [la] be for a lamb [le’imra]. Although this statement implies that what he does eat shall be considered like the lamb of the daily offering, Rabbi Meir holds that one cannot infer a positive statement from a negative statement. Conversely, that mishna is referring to a case where he said: For a lamb [le’imra]. In that case, his statement is interpreted as though he said: It shall be considered the lamb used for the daily offering, and therefore I will not eat it.

MISHNA: With regard to one who says: An offering, a burnt-offering, a meal-offering, a sin-offering, a thanks-offering, or a peace-offering, and adds: That which I eat of yours, the vow takes effect and the food is forbidden. Rabbi Yehuda renders the food permitted in all these cases. If one says: The offering, like an offering, or an offering, and adds: That which I will eat of yours, the food is forbidden. If he says: That which I will not eat of yours shall be for an offering, Rabbi Meir renders the food forbidden.

GEMARA: It teaches in the mishna that if one says: An offering, the offering, or like an offering, and then adds: That which I will eat of yours, it is forbidden. This indicates that this unattributed opinion in the mishna was taught in accordance with the opinion of Rabbi Meir, for whom there is no difference whether one says a lamb [imra] or as a lamb [le’imra].

The Gemara asks: However, if it is in accordance with the opinion of Rabbi Meir, that which it teaches is difficult. It teaches that if one says: The offering [hakorban], and adds: That which I will eat of yours, the food is forbidden. But isn’t it taught in a baraita that the Rabbis concede to Rabbi Yehuda that with regard to one who says: This offering [ha korban], or this burnt-offering [ha ola], or this meal-offering [ha minḥa], or this sin-offering [ha ḥatat], and then adds: That I will eat of yours, the vow does not take effect and the food is permitted? The reason for this is that the individual did not take a vow that the item should be associated with an offering; rather, he took a vow by the life of the offering, which is not a valid expression of a vow.

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Nedarim 13a explores whether vows can invoke a firstborn animal's sacred status, contrasting this with sin-offerings and guilt-offerings.