Bible Commentaries
Numbers 30

Verses 1-16

Numbers 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.

Numbers 30:2 Old Testament Quotes in the New Testament - Note a reference to Numbers 30:2 in Matthew 5:33, “Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths:”

Scripture References - Also, note a similar verse:

Ecclesiastes 5:4, “When thou vowest a vow unto God, defer not to pay it; for he hath no pleasure in fools: pay that which thou hast vowed.”