Gemara

45b (Mishnah - R. Meir): If one divorced his wife because of a vow that requires a Chacham to permit it, he may not remarry her. If the vow can be permitted without a Chacham, he may remarry her;

R. Yosi b'Rebbi Yehudah says, we were stringent about a vow that requires a Chacham only due to a vow that does not require a Chacham.

46a: R. Meir holds that a man does not mind if his wife is disgraced in Beis Din. (He can say 'had I known that a Chacham could permit the vow, I would not have divorced you. Your Get is invalid!')

The opposing opinion holds that a man does not want his wife to be disgraced in Beis Din. (He would have divorced her even if he knew.)

Nedarim 8b - Question (Ravina): Can a man be a Shali'ach for his wife to permit a Neder through regret? (Ravina wanted to do so for his wife.)

Answer (Rav Ashi): He may do so only if he finds (three) people already gathered. If not, he may not assemble a Beis Din to permit it.

We learn three things from this:

A man can be a Shali'ach for his wife's regret;

One cannot permit a Neder in his Rebbi's region;

A man can be a Shali'ach for his wife's regret only if three are already gathered.

Kidushin 81b (Beraisa): "Her husband annulled her vow; Hash-m will forgive her" discusses a woman who 'transgressed' her vow, unaware that her husband annulled it.

Rishonim

The Rif and Rosh (Nedarim 1:7) bring the Gemara.

Question (Re'em, cited in Rosh): Why is Shelichus needed? If the Chacham knows that the Noder (the one who vowed) regrets it, he can permit without the Noder's knowledge! Permission of a Chacham is like Hafarah (annulment) of a husband. "...Hash-m will forgive her" discusses one who was unaware that her husband annulled her vow (Kidushin 81b). The only difference between permission and Hafarah is the expression used to permit.

Answer (Re'em): Ravina's wife had asked Ravina to permit her vow. The Halachah follows Chachamim (Nega'im 2:5), who say that one can permit his wife's vow. Ravina wanted to honor his Rebbi, so he asked Rav Ashi whether or not a man can be a Shali'ach for his wife's regret without her knowledge. Perhaps she would be embarrassed, and she did not regret with intent for this! Rav Ashi is permitted only if he need not gather three, for then there is no publicity.

Question (Rashbam, cited in Rosh): One who divorced his wife due to a vow cannot remarry her, lest he say that the divorce was a mistake. Some say that this does not apply to a vow that requires Heter Chacham, for surely he did not want her to be disgraced in Beis Din. If a Noder can send a Shali'ach to Beis Din, there is no disgrace!

Answer (Rosh): R. Tam says that there is disgrace even through a Shali'ach. This is why we allow a widow to sell property outside of Beis Din. We do not say that she should make a Shali'ach to get permission! All the more so there is disgrace when people will find out that she vowed. R. Shimshon proved from Kidushin 81b that one may send regret with a Shali'ach, and Beis Din permits in his absence.

Ritva (on Rif Nedarim 25b DH Garsinan): Some say that that obviously, anyone else may be a Shali'ach. We ask only about a husband. Are we concerned lest he add to her regret because he wants to permit it?

Nimukei Yosef (Nedarim 2a DH Ba'al): Alternatively, perhaps she wanted him to annul it, but she did not want others to be involved. Even Shelichus is not needed. The Chacham only needs to know that the Noder regrets the vow. We learn from Kidushin 81b that a husband can annul without his wife's knowledge. The same applies to a Chacham.

Rejection (Ritva, citing his Rebbi): If we are not concerned lest others add to the regret, the same applies to a husband. All the more so he does not want her to transgress, for this causes her children to die (Shabbos 32b)! Rather, surely, anyone else cannot be a Shali'ach, for the Noder himself must tell his regret to Beis Din. We ask only about a husband. Since it is not normal for a woman to go to Beis Din, perhaps she can ask through her husband, for one's wife is like himself. B'Di'eved, it is not clear if regret through a Shali'ach helps for someone else. My Rebbi was stringent.

Nimukei Yosef (DH Iy): If he needs to gather three, we are concerned lest he add to the regret. R. Shimshon ruled that one may write his regret and send it to a Chacham to permit his vow in the absence of the Noder. He brings a proof from Kidushin, and from the Yerushalmi, which allows permitting through a translator. The Rashba and Rosh agree.

Tosfos (Nedarim 8b DH Omar): If he needs to gather three, perhaps he will forget her Pesach of regret, and add his own ideas to make it sound proper.

Me'iri (Nedarim 8b DH Huzkar): Some say that if we see him pursuing a Heter, e.g. he gathers people, or goes to a Chacham. we suspect him. It is permitted only if he chances upon a Chacham or three people.

Rambam (Hilchos Shevuos 6:4): The Noder, whether a man or woman, must come in front of the Chacham to permit the oath. One cannot make a Shali'ach to request permission. A husband can be a Shali'ach for his wife's regret, and they permit her, on condition that the three were already gathered. One may not gather three to permit her l'Chatchilah. One may not become a Shali'ach to permit his wife's Neder.

Me'iri (ibid., DH Huzkar): These final words teach that after the Pesach becomes clear, she must come in front of them to become permitted.

Hagahos Maimoniyos (2): Some texts say that Ravina's wife had been excommunicated, and he wanted to be a Shali'ach to permit her. According to this, there is no proof about being a Shali'ach for regret.

Poskim

Shulchan Aruch (YD 228:16): The Noder must come in front of those permitting. He cannot make a Shali'ach to permit his vow.

Beis Yosef (DH Kosav ha'Rambam): The Rambam says so. We learn from the Yerushalmi, which asks whether or not we may permit through a translator. This implies that obviously, we may not permit through a Shali'ach. We allow a translator because the Noder himself is there. The Ro'oh, Hagahos Maimoniyos, and Mordechai (Kidushin 550) agree. The Rashba allows through a Shali'ach, or by sending his regret in his handwriting. This is even better than Shelichus; perhaps it helps even if Shelichus does not. The Rosh cites the Re'em, who does not even require Shelichus. The Ran did not side with either opinion. The Rivash is stringent like the Rambam; the episode with Yiftach's daughter supports him. (Bereishis Rabah 60:3 - Yiftach wanted Pinchas to come to him to permit his vow, and Pinchas wanted Yiftach to come to him, so the vow was not permitted.)

Taz (20): The proof from Yiftach's daughter shows that even his handwriting does not help.

Rema: We can permit through a translator.

Shulchan Aruch (234:56): A husband can be a Shali'ach for his wife's regret, as long as the three were already gathered. He may not gather them.

Taz (46): The Noder must come in front of Beis Din. Any other Shali'ach does not help, only a husband, for he is like his wife.

Taz (47): The Ran (8b DH Ba'al) says that we were lenient to allow the husband to be in place of his wife, but only if three are already assembled.

Shach (71): He cannot gather them because she does not want publicity. If she consented, he may gather them.

Bach (DH v'Nir'eh): The Re'em explains that Ravina's wife asked him to permit her vow. Had she made him a Shali'ach, he could have assembled three. The Rambam forbids assembling three even if he was a Shali'ach.

Question (Mar'eh ha'Panim Nedarim 35a DH Rebbi): The Gemara said 'we learn that he can be a Shali'ach only if three are already gathered.' It did not specify that this is only if she asked him to permit it himself!

APPLICATIONS

Note: Our custom is that everyone annuls vows on Erev Rosh Hashanah, even if he does not know that he vowed. Surely there is no shame if a man gathers three for this! Presumably, even the Ran (cited in the Taz) would agree, for we want everyone to annul, and especially if she does not know that she has any vows!