Do not allow your mouth to cause your flesh to sin, neither say before the angel that it was a mistake. Why should the true God become indignant on account of your voice and have to wreck the work of your hands?”​—Eccl. 5:4-6.

Careless speaking with the mouth can put the body of flesh under obligation to do something that may be very difficult, leading to a failure to fulfill the vow and thus causing the flesh to sin. Careful forethought to one’s making a vow will prevent rash speaking. There will then be no desire for release from a vow, maintaining that it was a mistake.

Failure to fulfill a vow may have very serious consequences. Jehovah God may become “indignant,” withdrawing his favor and blessing, at least partially. As a result, what the individual may have built up is ‘torn down.’