Support #1: This is also the reason for one who is Matfis in Terumas Lachmei Todah after Zerikah, and one who is Matfis in Bechor after Zerikah;

He is not forbidden, like is proven from the Sugya below, even though they are forbidden to Zarim. Since they are permitted to Kohanim, [this shows that] the Isur is not due to his vow.

If they were due to his vow, they should be forbidden to everyone! Rather, it is an Isur that the Torah imposed on it. He is Matfis in Davar ha'Asur.

Support #2: This is also the reason why one who is Matfis in Chalas Aharon and his [Aharon's, i.e. Kohanim's] Terumah, it is permitted. The Isur is not due to his vow. Rather, it is a Gezeras ha'Kasuv. So it seems to me.

Gemara: Behold, Nosar and Pigul are after Zerikah!

Explanation: Some texts do not say Pigul, for once it became Pigul, Zerikah does not permit it. (Even our text says 'Hu' (singular)! - PF)

Rather, the question is from Nosar. The Isur of his vow ended with throwing the blood, and even so, the Mishnah forbids. We infer that he is Matfis is the initial state.

Gemara: In Nosar of an Olah.

Explanation: Even if you will say that he is Matfis in the current state, still, his vow (to make it an Olah) was not uprooted, for Olah is forbidden even after Zerikah.

Explanation: Granted, if you will say that we do not discuss an Olah, it mentioned Nosar to teach that he is Matfis in the initial Isur;

However, if you will say that we discuss an Olah, what is the Chidush of Nosar? Still, his Neder was not uprooted. If so, it should teach meat of an Olah!

Implied question: Based on what I explained in our Mishnah, that for Nosar and Pigul R. Yehudah does not require a Kaf of comparison...

We should have answered this is why it taught Nosar, and not meat of an Olah, to teach that these forbid even without a Kaf of comparison!

Answer: The Gemara gave a better answer. (It is a Chidush that Nosar is not considered Hatfasah in Devar ha'Asur. - PF)

Gemara: This is if he vowed on that day.

Explanation: Now we are thinking that he vowed only about the day that his father died, that he will not eat meat, and so he vowed once not to eat meat on the day that Gedalyah died, and now he is Matfis one day like that day;

Since he vowed about it initially, now he is Matfis in Devar ha'Nadur (something forbidden due to a vow).

Explanation: He says on Sunday, which is like the day that his father died according to the count of months, e.g. it was Sunday of the first week of Nisan;

[He said] 'this day will be Alai like Sunday of the first week of Nisan."

Inference: Even though there are many permitted Sundays, it teaches that he is forbidden! This teaches that he is Matfis in the initial Isur.

Source: The Gemara infers that this is the case, for if he explicitly said that this day is like the day his father died, obviously he is forbidden!

Rather, surely he said "this day will be Alai like Sunday of the first week of Nisan." The Chidush is, even though we could have said that he is Matfis in Heter...

(We do not.) Since it is now the same day according to the count of months, like the day his father died, and he is Matfis and says "this day will be Alai like Sunday", he is Matfis in the initial Isur, and he is forbidden.

Explanation: The case is that all Sundays that passed, which are like the day that his father died, were forbidden to him due to a Neder;

Therefore, we cannot learn this law from here, and say that it teaches this Chidush, for here there are no days of Heter at all.

Explanation #1: This Sugya is truncated. The Gemara did not explain if so, what does it comes to teach us? Rather, it relied on the Sugya in Shevu'os (20a);

We say there exactly like here. Shmuel said that this is if he had already vowed from that day;

Afterwards it asks "the day that his father died? This is obvious!", and answer that the day Gedalyah was killed is the Chidush.

We ask that also this is obvious, and answer that one might have thought that since even if he had not vowed, it is forbidden mid'Rabanan, even when he vows, his vow does not take effect, and he is not Matfis in a vow. The Beraisa teaches that this is not so. So it seems to me.

Explanation #2: Alternatively, this Sugya holds that even though it is unlike a Korban, which is forbidden to everyone, for here it is forbidden only to himself, even so, it is called Matfis in Davar ha'Nadur.

From the conclusion in Shevu'os we learn to one who vowed [not to eat] cheese of Nochrim or their Stam wine (it was not offered to idolatry), or the fat of Gid ha'Nasheh, and he was Matfis in them. He is Matfis in the Neder, and he is forbidden.

Gemara: Like the Chalah of Aharon and his Terumah', he is permitted.

Explanation: Even though it is forbidden via calling it so, since it is not forbidden to all, it is called Davar ha'Asur, and not Devar ha'Nadur.

Gemara: But [had he said] 'like Terumah of Lachmei Todah...

Explanation: One loaf that [the Kohen] takes from every 10 loaves, from every kind [of bread] in it (brought with the Todah).

Gemara: It is forbidden.

Explanation: For he is Matfis in Devar ha'Nadur.

Gemara: Behold, Terumas Lachmei Todah is after the blood was thrown!

Explanation: Since Lachmei Todah are permitted to eat only after Zerikah, why would they separate them beforehand?!

Inference: Since it taught 'it is forbidden', we learn that he is Matfis in the initial Isur.

Gemara: Rather, say that had he said 'like Terumas ha'Lishkah', it is forbidden.

Explanation: Terumas ha'Lishkah, that they take from coins (half-Shekalim) in the chamber (for Korbanos Tzibur), and they fill three boxes.

Gemara: Let it teach Terumas Lachmei Todah, and all the more so his Terumah!

Explanation: It would be a bigger Chidush, for initially Terumas Lachmei Todah was forbidden via a vow.

Gemara: It is his Terumah.

Explanation: I.e. it is included in 'and like his Terumah' that was taught, because it is like Terumah regarding Zarim.

Gemara: Terumas Lachmei Todah is also before throwing the blood!

Explanation: I.e. we find that it was separate before Zerikas Damim, and therefore [the Tana] could not teach uniformly 'like Terumas Lachmei Todah', for there is a case in which it is forbidden, when Terumah was taken before Zerikas Damim.

Implied question: Really, we could have answered that he separated them after they were baked, before Zerikah;

They were [always] baked even before Shechitah of the Zevach (Todah), for it says in Menachos (78b) that if the Zevach was slaughtered before the faces of the bread formed a crust, [the bread] did not become Kodesh.

Answer: Rather, since we bring a proof from Rav Tuvi that he can separate before Zerikah, and Rav Tuvi discusses when he separated them when they were kneaded (before they were baked), also here we discuss when he separated them when they were kneaded.

Gemara: With four loaves.

Explanation: Four kinds of loaves.

Gemara: Behold, it is written 40!

Explanation: For there are four kinds - Chametz, loaves, wafers and Revuchah, and it is written "he will offer one from each Korban"! (We explain according to the Hagahah, that this is all one Dibur.)

I.e. [one] from each kind. We learn from a Gezeirah Shavah that this is one from 10, so there are 40 [loaves]!

Gemara: He took one of Chametz.

Explanation: He made 10 loaves of each kind, and after he separated one from each kind, he kneaded [together the remaining] nine of each kind, and made one loaf from each of the nine.

Explanation: "If it is before Zerikah", i.e. he said so explicitly.

Assertion: It seems to me that really, we could have asked, if he said 'it is Alai like a Bechor' Stam, what is the reason for the one who permits?

Even if we say that [when a Devar ha'Nadur that became permitted is in front of a person, and he is Matfis in it,] he is Matfis in Heter, anyone who says Stam (when it is not in front of him), he is Matfis in the initial Isur.

Source: Our Mishnah teaches "Chatas, Todah, Shelamim, he is forbidden." Why don't we infer from it in our Sugya that he is Matfis in the initial Isur? (Rather, we cannot, for the Mishnah discusses Stam, and our Sugya asks about Hatfasah in an item (Devar ha'Nadur) that became permitted. - PF)

Explanation: Since we needed to say "if it is after Zerikah, what is the reason for the one who forbids?", we said also "if it is before Zerikah, what is the reason for the one who permits?" However, also Stam was difficult.

Gemara: No, according to all it is before throwing the blood.

Explanation: I.e. alternatively, Stam, for they have the same law. And even so, R. Yosi permits, for it is written "Ki Yidor Neder", and Bechor is Davar ha'Asur, for Bal Korcho (against his will), Kedushah takes effect on it.

Gemara: "La'Shem", to include Davar ha'Asur.

Explanation: I.e. since there is a Mitzvah to be Makdish it, like the Gemara explains below. (The inclusion is for such a case, but not for any Davar ha'Asur. - PF)

Explanation: Even though he is obligated to bring them, they are called Davar ha'Nadur more than Bechor.