The Lord shall forgive her. Numbers 30:5,8,12
If the father or husband disallowed the vow a woman made, it would not stand, nor would she be held responsible for its fulfillment. God would not keep her to a promise which was hindered from execution by causes over which she had no control. This is a profound principle.
You may feel that a certain step is required of you by Christ; that indeed you are bound by your allegiance to Him to take it; nay, you have already promised Him that you will take it; but, suddenly and most unexpectedly, you are prevented from taking it. The express prohibition of those who have a right to determine your action, or the verdict of the physician, or the evident call of duty in another direction, makes it needful for you to relinquish your project. What then: is God grieved and angry? Not so; He understands the whole of the case perfectly, and accepts your will for the deed, and bids you go in peace. This, however, does not affect matters in which conscience is clear in demanding or prohibiting a certain line of conduct.
Sometimes God's silence is consent. You made your solemn dedication in His holy presence: there was no answering voice, or rush of emotion, or witnessing seal; He held His peace from day to day. But in that silence He established all your vows, all your bonds.
If parents capriciously forbid their children carrying out solemn resolutions and vows, the burden of blame must rest on their shoulders. They must render their account to God, and give answer for their action. It will go hard with those who put needless hindrances and obstacles in their brothers' pathway.