2 When a man makes a vow to God or binds himself by an oath to do something, he must not break his word; he must do exactly what he has said.
3 "When a woman makes a vow to God and binds herself by a pledge as a young girl still living in her father's house, 4 and her father hears of her vow or pledge but says nothing to her, then she has to make good on all her vows and pledges. 5 But if her father holds her back when he hears of what she has done, none of her vows and pledges are valid. God will release her since her father held her back. 6 "If she marries after she makes a vow or has made some rash promise or pledge, 7 and her husband hears of it but says nothing to her, then she has to make good on whatever she vowed or pledged. 8 But if her husband intervenes when he hears of it, he cancels the vow or rash promise that binds her. And God will release her. 9 "Any vow or pledge taken by a widow or divorced woman is binding on her. 10 "When a woman who is living with her husband makes a vow or takes a pledge under oath 11 and her husband hears about it but says nothing and doesn't say she can't do it, then all her vows and pledges are valid. 12 But if her husband cancels them when he hears about them, then none of the vows and pledges that she made are binding. Her husband has canceled them and God will release her. 13 Any vow and pledge that she makes that may be to her detriment can be either affirmed or annulled by her husband.
Matthew Henry's Commentary on Numbers 30:2-13
Commentary on Numbers 30:1-2
(Read Numbers 30:1-2)
No man can be bound by his own promise to do what he is already, by the Divine precept, forbidden to do. In other matters the command is, that he shall not break his words, through he may change his mind.
Commentary on Numbers 30:3-16
(Read Numbers 30:3-16)
Two cases of vows are determined. The case of a daughter in her father's house. When her vow comes to his knowledge, it is in his power either to confirm it or do it away. The law is plain in the case of a wife. If her husband allows her vow, though only by silence, it stands. If he disallows it, her obligation to her husband takes place of it; for to him she ought to be in subjection, as unto the Lord. The Divine law consults the good order of families. It is fit that every man should bear rule in his own house, and have his wife and children in subjection; rather than that this great rule should be broken, or any encouragement be given to inferior relations to break those bonds asunder, God releases the obligation even of a solemn vow. So much does religion secure the welfare of all societies; and in it the families of the earth have a blessing.