If a person forbids something tangible to himself even without swearing an oath, he must fulfill his vow and he is forbidden to violate it, as it says "[If a man makes a vow...] to forbid himself something, his word shall not be annulled; he must do everything that comes out of his mouth"¹; and it says "[If you make a vow...] you must keep and do what comes out of your lips".^2,a He must forbid it by saying that it is like something which it is in his power to make forbidden -- e.g., like a sacrifice or other donation to the Temple that can be brought by an individual.^b A person can also forbid his own property to others.^c

As with oaths, a vow must be expressed orally and with intent; it can be administered by others; it is not binding if made under duress or in ignorance of the facts or in exaggeration; and one can be released from it in the same way as from an oath. Unlike oaths, however, one can include oneself in a vow made by another and can extend the scope of a vow to new things; and one can forbid to himself things necessary for the fulfillment of a commandment.^d

A father can annul the vows and oaths of his young unmarried daughter on the day he hears them, as it says ["And if a woman makes a vow... in her father's house in her youth... and her father opposes her on the day he hears], all her vows and prohibitions that she made on herself do not stand, and Ha-Shem will forgive her since her father opposed her".³ Similarly, a husband can annul his wife's vows and oaths even if he does not hear them, as it says "And if she made a vow in her husband's house... and if her husband annulled (it) on the day he heard... it does not stand...; any vow or oath to prohibit, to afflict... her husband can annul it".⁴ A husband can completely annul a vow only if it involves affliction; otherwise, he can annul it only as regards himself but not as regards others.^e