Numbers — Chapter 30

When a man shall make a vow to the Lord, or bind himself by an oath, he shall not break his word but shall do all that he promised. The sacredness of vows; Lapide compares this to religious vows in the New Law, which are binding under pain of grave sin.

A woman's vow may be annulled by her father or husband on the day he hears it; if he is silent, the vow stands. Lapide: husbands and fathers have authority to direct the devotional life of their households, provided they do so for good reason.