Vows

voluntary promises which, when once made, were to be kept if the
thing vowed was right. They were made under a great variety of
circumstances (Gen. 28: 18-22; Lev. 7:16; Num. 30:2-13; Deut.
23:18; Judg. 11:30, 39; 1 Sam. 1:11; Jonah 1:16; Acts 18:18;
21:23).