Numbers 30

The Israelites were expected to keep their word, just as they expected the LORD to keep his promises to them. 

Men, widows and divorced women were under their own authority, so they were responsible to keep their vows, no matter what.

Unmarried women could be excused of their vows by their fathers, and married women could be excused of their vows by their husbands.  In both these cases, the emphasis is still on responsibility.  The father and husband would be the ones responsible for seeing that the vow is carried out.  If they do not say anything when they hear of the vow, they must be responsible to see that it is carried out.

Jesus warns us not to make rash vows:

“Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil” (Matthew 5:37).

Vows are often a type of bargaining with God.  It is very hard to keep such promises, but we are responsible for what we promise.

LORD, give us the wisdom not to promise too much.