Vows

[Num. 30:2] If a man vow a vow unto the LORD, or swear an oath to bind his soul with a bond; he shall not break his word, he shall do according to all that proceedeth out of his mouth.
1-16 vows are not to be broken! The subject of this chapter relates to vowing, which seems to have been an ancient usage, allowed by the Law to remain, and by which some people declared their intention of offering some gift on the altar or abstaining from particular articles of meat or drink, of observing a private fast, or doing something to the honor or in the service of G-d, over and above what was authoritatively required. In 29:39, mention was made of "vows and freewill offerings," and it is probable, from the explanatory nature of the rules laid down in this chapter, that these were given for the removal of doubts and difficulties that conscientious persons had felt about their obligation to perform their vows in certain circumstances that had arisen.
If a man vow a vow unto the L-rd, a mere secret purpose of the mind was not enough to constitute a vow; it had to be actually expressed in words; and though a purely voluntary act, yet when once the vow was made, the performance of it, like that of every other promise, became an indispensable duty - all the more because, referring to a sacred thing, it could not be neglected without the guilt of prevarication and unfaithfulness to G-d.
He shall not break his word - literally, "profane his word" - render it vain and contemptible (Ps. 55:20, 89:34). But as it would frequently happen that parties would vow to do things which were neither good in themselves nor in their power to perform, the law ordained that their natural superiors should have the right of judging as to the propriety of those vows, with discretionary power to sanction or interdict their fulfillment. Parents were to determine in the case of their children, and husbands in that of their wives--being, however, allowed only a day for deliberation after they knew the matter; and their judgment, if unfavorable, released the devotee from all obligation (30:3-8).
This involved going to a teacher/spiritual leader or three ordinary men and follow the biblical record for annulling a vow that for some reason you made and physically cannot keep. If this is not done the name of the L-rd is used in vain and it was a very serious thing. It was forbidden to break one’s word in vows made; you must mean what you say and say what you mean.
If a woman also vow a vow unto the Lord, and bind herself by a bond, being in her father's house in her youth - Girls only are specified; but minors of the other sex, who resided under the parental roof, were included, according to Jewish writers, who also consider the name "father" as comprehending all guardians of youth. We are also told that the age at which young people were deemed capable of vowing was thirteen for boys and twelve for girls. The judgment of a father or guardian on the vow of any under his charge might be given either by an expressed approval or by silence, which was to be construed as approval. But in the case of a husband who, after silence from day to day, should ultimately disapprove or hinder his wife's vow, the sin of non-performance was to be imputed to him and not to her (30:15).
In the days speedily, or without delay, allowing only convenient time for deliberation. And it is hereby intimated, that the day or time he had for disallowing her vow, was not to be reckoned from her vowing, but from his knowledge of her vow.
The L-rd shall forgive or, will forgive her not performing it. But this should be understood only of vows which could not be performed without invading the father’s right; for if one should vow to forbear such, or such a sin, and all occasions or means leading to it, and to perform such, or such duties, when he had opportunity, no father can discharge him from such vows. If this Law does not extend to children’s marrying without the parent’s consent, so far as to put it in the power of the parent, to disannul the marriage, (which some think it does) yet certainly it proves the sinfulness of such marriages, and obliges those children to repent and humble themselves before G-d and their parents.
Every vow of a widow in the case of a married woman, who, in the event of a separation from her husband, or of his death, returned, as was not uncommon, to her father's house, a doubt might have been entertained whether she was not, as before, subject to paternal jurisdiction and obliged to act with the paternal consent. The Law ordained that the vow was binding if it had been made in her husband's lifetime, and he, on being made aware of it, had not interposed his veto (30:10-11); as, for instance, she might have vowed, when not a widow, that she would assign a portion of her income to pious and charitable uses, of which she might repent when actually a widow; but by this statute she was required to fulfill the obligation, provided her circumstances enabled her to redeem the pledge. The rules laid down must have been exceedingly useful for the prevention or canceling of rash vows, as well as for giving a proper sanction to such as be legitimate in their nature, and made in a devout, reflecting spirit.
To afflict her soul, herself by fasting, by watching, or the like. And these words are added to shew that the husband had this power not only in those vows which concerned himself or his estate, but also in those which might seem only to concern her own person, or body, and the reason is, because the wife’s person or body being the husband’s right; she might not do any thing to injury of her body without his consent.
Her husband may establish it, or her husband may make it void. After he hath heard - and approved them by his silence from day to day, if after that time he shall hinder it, which he ought not to do: her non-performance of her vow shall be imputed to him, not to her.