Even though a boy who has not yet reached the age of bar mitzvah is not obligated by Torah law in any of the mitzvot, there is a rabbinical command for a father to train his child even at a young age in the performance of mitzvot. Does this parental obligation of chinuch extend to the mother as well, and does it apply to training a daughter as well as a son?

The impression gained from our gemara is that the responsibility of chinuch is limited to a father training a son. The Sage Reish Lakish explains the mishna ruling that a father can impose on his pre-bar mitzvah age son a vow to be a nazir as being a function of chinuch and not a Torah law. When challenged as to why it is only the father who can impose such a vow and only in regard to a son, Reish Lakish responds that a mother is exempt form the obligation of chinuch, and that even a father is responsible only for the chinuch of a son and not of a daughter.

Regarding a mother's obligation for chinuch there is a difference of opinion amongst the authorities. Magen Avraham (Shulchan Aruch, Orach Chaim 243:1) concludes from our gemara that she has no such obligation, and that Queen Helenie's training of her young children in the mitzvah of succah (Mesechta Succah 2b) was something she did voluntarily. Machatzit Hashekel, however, cites authorities who contend that a mother is also obligated as the case of Queen Helenie would indicate, and dismiss the view stated in our gemara as the position of Reish Lakish which is not in accordance with the halacha.

With respect to the parental obligation to train a daughter, even Magen Avraham agrees that the rabbinical mitzvah of chinuch applies to girls as well. This is based on the observation made by Tosefot here that the gemara (Mesechta Yoma 82a) clearly states that a parent should train both underage sons and daughters in fasting on Yom Kippur. Since this seems to be in direct contradiction to what Reish Lakish says in our gemara, Tosefot concludes that some distinction must be made, but does not elaborate on what that distinction is.

Magen Avraham expresses an uncertainty as to the nature of this distinction: It is either that fasting on Yom Kippur is such an important mitzvah because it is a day of atonement, and therefore even a girl should be trained, while chinuch will not apply to her in other mitzvot; or that all mitzvot are like fasting on Yom Kippur and she should be trained in all of them except for the mitzvah of nezirut which is not really obligatory and may never be relevant to her adult life. He cites a midrash (Yalkut Parshat Emor) which supports the latter approach, and Machatzit Hashekel cites a Tosefot Yeshanim (Yoma ibid.) to the same effect. This is why the halachic authorities such as Mishna Berura categorically state that chinuch applies to daughters as well as sons.

The general rule regarding a sage's annulment of a vow is that he cannot suggest to the vow-maker an opening of regret at having made the vow based on something which happened after the vow was made. [Even Rabbi Eliezer, who initially held (Mesechta Nedarim 64a) that such an opening could be used for annulment, eventually came around to the position of the other sages, as is evident from his dissenting opinion not being mentioned in our mishna here.] The logic of this is that when one takes a vow he does not even consider that something improbable will happen, so we view his vow as being a categorical commitment which cannot be annulled on the basis of his having made that vow in error.

One of the examples cited in the mishna of this principle has an interesting historical background. Some people had taken vows of nezirut outside of Eretz Yisrael. When they came to Jerusalem to offer the sacrifices incumbent on a nazir at the end of his period, they were disappointed to find that the Beit Hamikdash had been destroyed. Unable to be liberated from their nazir status because they could not offer the necessary sacrifices, they sought annulment of their vows. One sage, Nachum Hamodi, asked them whether they would have made their nazir vows had they known the Beit Hamikdash would be destroyed. When they answered in the negative he annulled their vows. This was an erroneous judgment, says the mishna, and it was overturned by the other sages because this is a classic example of regret based on something which took place only after the vow was made.

Rabbi Yosef added an interesting postscript to this story. Had he been in Jerusalem when these nezirim came, he declared, he would have chided them for making such a vow without fear that the Beit Hamikdash would be destroyed as prophesied by Yirmiyahu (7:4). The Sage Abaye, however, rallied to the defense of these nezirim by pointing out that even if they were aware of this possibility, and even if they could calculate the year of destruction based on a passage in Daniel (9:24), they could still have assumed that their period of nezirut would end before the destruction took place in that year.

Nazir 32b