2,864. An Underage Nazir

Hilchos Nezirus 2:13

When a minor reaches the age at which vows become effective (i.e., 12 for a boy and 11 for a girl), if he makes a nazirite vow, he is rendered a nazir and must bring the offerings. This is so even if he hasn’t yet developed the physical signs of maturity, just like with other vows. A father may impose a nazirite vow on his minor son even if he hasn’t reached the age at which vows become effective; a woman, however, cannot impose such a vow on her son. This law was transmitted via our oral tradition and doesn’t apply to other types of vows.

Hilchos Nezirus 2:14

Pursuant to the previous halacha, if father tells his minor son, “You’re a nazir,” or if he says that his son is a nazir, either identifying him by name or pointing to him, if the son remains silent, he is rendered a nazir. The father must have him act according to all the laws of a nazir. If the son is rendered unclean through a corpse, he must bring the necessary offering. When he fulfills his term as a nazir, he must bring that offering, just as adult nazirs do.