Gemara: We lash him.

Explanation: For a vain Shevu'ah.

Gemara: And he sleeps immediately.

Explanation: If he wants to, for the Shevu'ah does not take effect to forbid him at all.

Question: Also here, how does his Neder take effect?

Explanation: This is because we cannot establish it that he said "Konam my eyes from sleeping today", for if so, this is obvious!

Rather, it means that he must be careful not to sleep the first day of the Tenai, lest he come to Bal Yachel.

Support: This is why it taught "Bal Yachel Devaro applies to him", and not "he is forbidden", for it is not correct to teach [the latter];

The first day is not forbidden due to itself, rather, only lest he come to Bal Yachel on the second day.

Gemara: Behold, you said that one is always careful about his Isur!

Explanation: Therefore, you cannot say so.

Explanation: Our Mishnah teaches that Bal Yachel Devaro applies to him, i.e. he may come to a Safek (situation in which he might transgress) Bal Yachel. If he wants, he may sleep on the first day.

And we do not say that he may not sleep, lest it be possible to come to Bal Yachel.

Question: We asked above "you said that one is always careful about the Isur!" What was the question?

We should say 'Bal Devaro applies to him" means that he may sleep on the first day, and enter a Safek Bal Yachel, because one is careful about the Isur!

Also now, we explain like this!

Answer: The reason we could not say so [above] is because if it teaches Heter [to transgress the Tenai] because one is careful about the Isur, he should have taught first (i.e. rather) the Isur [to transgress the Isur itself] because people are not careful about the Tenai.

Justification: Rav Yehudah taught that one is not careful about the Tenai - this is a mere concern mid'Rabanan. It is not so obvious, for Rav Nachman argues with it!

Why did the Tana rush to teach Heter, which we hear automatically, and everyone agrees to it, and he did not teach the Isur of Tenai, which is a big Chidush?

This is why we conclude that surely, the Tana teaches the Heter of (due to) a Tenai, that one [may transgress the Isur, for he] is careful even about the Tenai, and Rav Yehudah is refuted.

Gemara: It taught if he slept.

Explanation: Just the contrary! The Mishnah comes to teach Rav Yehudah's law!

It teaches as follows. He must be careful not to sleep on the first day, for if he sleeps, he is likely to come to Bal Yachel, for one is not careful about the Tenai.

Explanation: [The Mishnah discusses Konam] what I will sleep. He did not say [Konam] my eyes from sleeping. Even though it is intangible, there is Bal Yachel mid'Rabanan.

We find a Tana who taught that "Lo Yachel Devaro" applies mid'Rabanan. This is why the Tana of our Mishnah in Nedarim taught "Lo Yachel Devaro applies to him", and he did not teach "he is forbidden", like it taught in [15b, in the Mishnah of] Shevu'os.

This is because in Shevu'os, he is forbidden via letter of the law, but in Nedarim, he is forbidden only mid'Rabanan, due to [concern for] Bal Yachel.

Gemara (Mishnah): What you benefit Li (me).

Explanation: I.e. from my property.

Gemara: If you will go to your father's house...

Explanation: If she went, she is forbidden, but if she did not go, no. She may benefit before Pesach, as long as she does not go;

Inference: Even though 'what you benefit from me' is the Isur, and 'if you will go to your father's house' is the Tenai, [she is permitted as long as she did not go]. We learn that one is careful even about Tena'im!

Explanation #1: She is lashed, but he is not lashed, for he did not do any Isur. He merely forbade her through a vow;

Perhaps our Tana also teaches by the way that the Isur is on her, but not on him at all.

Explanation #2: The Rambam wrote that he, who was Madir her, is lashed, if he benefits her;

However, she is not lashed. Since she did not vow at all, "Lo Yachel Devaro" does not apply to her.

Rejection: This is wrong. Surely he is not lashed, since it says below (35a) regarding "Me'ilah applies to Konamos"...

Citation (35a) Question (Rav Acha brei d'Rav Ika, of Rav Ashi): [If one said] "my loaf is [Konam] to you", and he gave it to him for a gift, who transgresses Me'ilah? The giver cannot transgress, for it is not forbidden to him!

Inference: The one who forbids does not transgress at all, and the Mudar (who was forbidden) surely transgressed;

Even though it says "Lo Yachel Devaro", Lo Yachel refers to the utterance. (The Mudar transgresses for profaning the utterance, even though he did not say it.)

Proof - Citation (Nidah 46b): We find that the Torah equated a minor to an adult for intentional transgression of a Shevu'ah, and Isur, and Bal Yachel;

The Gemara explains there that this refers to the Isur of Bal Yachel, e.g. he (the minor) was Makdish it, and others (adults) ate it. The others are lashed for his Hekdesh, due to Bal Yachel.

Inference: The Mudar is lashed, even though he did not say anything.

Conclusion: Therefore when we say here "[the person] is lashed", it refers to the woman.

Gemara: It taught that if she [transgressed and] benefited, [she] transgresses Bal Yachel Devaro.

Explanation: I.e. this itself it teaches us, that she must be careful not to benefit before Pesach, in order that if she goes after Pesach, she will not come to Bal Yachel.

Gemara: She may go after Pesach.

Explanation: We are not concerned lest she not remember that she transgressed the Tenai before Pesach, and if we permit her to go, she will come to benefit...

And one might have thought that she should be forbidden to go mid'Rabanan, in order that she will remember that she is forbidden to benefit; [the Mishnah teaches] that this is not so.

Implied question: Why did we think that "Achal" means that he may eat? (It connotes b'Di'avad!)

Answer: It is because [the Tana] taught all the Isurim. He taught 'if he ate, Bal Yelach applies to him. If he went, Bal Yachel Devaro applies to him...'

If l'Chatchilah he may not eat, he should have taught also this Isur [to eat l'Chatchilah]!

Gemara: And we answer, did it teach 'he may eat'? It taught 'if he ate'!

Explanation: Since it taught "he ate", which implies b'Di'avad, this teaches that l'Chatchilah he may not eat.

Gemara: We ask further, consider the Seifa. "If he went, Bal Yachel Devaro applies to him." It did not teach that he may go! (This is unlike our text in the Gemara. Hagahos Yeshanos brings this text.)

Explanation: I.e. if Rav Yehudah's law is correct, [the Seifa] should have taught "he may go. Bal Yachel Devaro does not apply to him", and it is an independent matter. It does not refer to the Reisha;

Rather, it should have taught 'he may go, and Bal Yachel does not apply to him.' Presumably this is so, for he may not eat on the first day;

Why did [the Tana] say uniformly "if he went, Bal Yachel applies to him"? [This is difficult,] since he should not eat on the first day!

Explanation: I.e. indeed, if he wanted to teach the matter by itself, he would have taught "he may go";

Rather, since above he taught "if he ate", and he could not have taught "he may eat", therefore he did not teach "he may go, and Bal Yachel does not apply to him."

Had he taught so, it would connote that even if he ate on the first day, he may go on the second day, and Bal Yachel does not apply;

Explanation (cont.): We would explain the entire Beraisa as follows. Sometimes if he ate, Bal Yelach applies to him;

This is if he ate b'Mezid, i.e. he remembered that the Isur to go depends on his eating;

And sometimes, even though he ate on the first day, he may go on the second, e.g. if he ate on the first day b'Shogeg. I.e. he did not remember at the time he ate that the Isur to go depends on his eating;

In such a case he may go on the second day, like is proven from the Sugya of loaves in Shevu'os (28a).

Because the Tana was not engaging in this law, he taught "if he went" in the Seifa. It seems to me that this is the correct text and Perush.

Remark: There is another text, but it is not precise. Therefore, I was not concerned to write and explain it.

Question: Since "if he went" in the Seifa refers to the Reisha, why must it teach "Bal Yachel applies to him"? This is obvious!

Answer: One might have thought that since at the time he ate he did not transgress, also when he went, Bal Yachel would not take effect on him retroactively. [The Beraisa] teaches that this is not so.

Gemara: And regarding the Halachah.

Explanation: We hold like Rav Yehudah, since we said above (14b) 'and R. Yehudah agrees that if he said "Konam my eyes to sleep tomorrow..."', and we discuss his opinion. We infer that the Halachah follows him.

Gemara: Behold, from the Torah he is obligated to her!

Question: What was the question? We say in Kesuvos (59b) that Konamos are Kedushas ha'Guf, and they uproot a lien!

Answer: Just like we say there that Rabanan strengthened the husband's lien, they strengthened also the woman's lien.

Explanation: I.e. if he forbade his body to her, indeed, he cannot, for mid'Oraisa he is obligated to her. This is like forbidding another's (Ploni's) property to Ploni!

Rather, here we discuss that he said "pleasure of Bi'ah with you is Alai." He forbids to himself relations with her. He can forbid to himself;

This is like Rav Kahana taught, that a woman can forbid pleasure of Bi'ah with her husband to herself.

Since there is his room for his vow [to take effect], its takes effect, and automatically the lien is uprooted.

Question: This vow is [only] mid'Rabanan, for pleasure of relations is intangible! (How can it break Shibud mid'Oraisa?)

Implied suggestion: The case is, he said "your body is Konam Alai for relations."

Rejection: This was taught like (the other cases in our Mishnah, i.e.) "that I sleep, or that I speak." Ravina established that Bal Yachel applies mid'Rabanan;

Summation of question: Since it is only mid'Rabanan, how can his vow, which is only mid'Rabanan, take effect and uproot the Mitzvos of Onah (relations at the proper times) and Peru u'Rvu?

Answer: Since the vow takes effect, automatically these Mitzvos are uprooted. Chachamim stipulate to uproot matters from the Torah passively (they tell a person to refrain).

Question: When he said "pleasure of Bi'ah with you [is Alai]", why is he forbidden? Mitzvos Lav Leihanos Nitnu!

Answer: We say that Mitzvos Lav Leihanos Nitnu, i.e. fulfillment of a Mitzvah is not considered Hana'ah, but in any case if his body gets Hana'ah at the time he fulfills the Mitzvah, this is called Hana'ah.

Support: This is why we say in Rosh Hashanah (28a) that one who vowed Hana'ah from a spring may immerse in it in winter, but not in summer.

Explanation: When he said "Korban Lo Ochel", if we say that he swears in the life of the Korban, he is permitted, because one cannot swear in a Korban (Shevu'ah is only in Hash-m's name).