3 When a man takes an oath to the Lord, or gives an undertaking having the force of an oath, let him not go back from his word, but let him do whatever he has said he will do. 4 If a woman, being young and under the authority of her father, takes an oath to the Lord or gives an undertaking; 5 If her father, hearing of her oath or the undertaking she has given, says nothing to her, then all her oaths and every undertaking she has given will have force. 6 But if her father, hearing of it, makes her take back her word, then the oaths or the undertakings she has given will have no force; and she will have forgiveness from the Lord, because her oath was broken by her father. 7 And if she is married to a husband at the time when she is under an oath or an undertaking given without thought; 8 If her husband, hearing of it, says nothing to her at the time, then the oaths she made and the undertakings she gave will have force.

Matthew Henry's Commentary on Numbers 30:3-8

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.