Vows are spoken promises made to God, and are often made in response to help received from God. A person making a vow can offer a thing, an action, or the promise of a future action. It is an act of trust between people and God. A person making a vow is expected to fulfill it by doing what is promised. Vows were used in various ways in the Bible.

A vow (in the CEV often translated as “promise”) is not the same as an oath. In general, an oath reassures others that the speaker of the oath is being truthful, whereas a vow involves a promise to God. The New Testament states that oaths should be avoided (Matt 5:34-37; Jas 5:12).

Sometimes vows were made to get something from God. In return for God’s help or blessing, the person making the vow promised to do something or give something. For example, Jacob promised to worship God and give God a tenth of everything he owned if God would protect him (Gen 28:20-22). The brave warrior Jephthah promised God he would sacrifice the first person who greeted him after battling the Ammonites if God let him win the battle (Judg 11). Hannah prayed for God to give her a son, and in return she promised to dedicate him to serve the Lord at Shiloh (1 Sam 1). And the sailors with Jonah made promises to God to calm a violent storm at sea (Jonah 1:13-16). See also Acts 21:23.

Other promises were simply made to thank God. Nothing was expected in return. King David promised that he would not rest until he had found a home for the Lord and the sacred chest (Ps 132:2-5).

God also made promises. God’s promises are always fulfilled (see Num 23:19). Though David didn’t ask for it, God promised that someone in David’s family would always be king (2 Sam 7; Ps 132:11,12). Some other examples of God’s promises or vows can be found in Genesis. In Genesis 8:21, the Lord promised never again to destroy everything that breathes, or to punish the earth for the sinful things its people do. In Genesis 12:2,3, the Lord promised to bless Abram and make his descendants into a great nation, and in Genesis 15:5,6, the Lord promised Abram as many descendants as there are stars in the sky.

The Law of Moses had rules for making promises or vows. There were laws about offerings given when making a vow of peace (Lev 7:16-18) and about what kind of offering was acceptable when making a sacrifice for a vow (Lev 22:17-25; Num 15:1-10). Laws also set the price to buy back people or property promised to God (Lev 27:1-25). There were special rules for those who dedicated themselves to God by vowing to become Nazirites (Num 6:1-21). It is possible that the apostle Paul was making a kind of Nazirite vow when he cut his hair and made a promise to God at Cenchreae (Acts 18:18).

Numbers 30 deals mostly with vows made by women. A young woman living at home could make a vow, but her father had the power to cancel it. If he did, she no longer had to keep the promise and would not be blamed. The same was true of a husband who disapproved of his wife’s vow. Widows and divorced women could make vows and were expected to keep them, because no one had the power to cancel their vows. Making a promise to the Lord was not required, but when a promise was made, the Lord expected it to be kept (Deut 23:21-23; Eccl 5:4,5).