'Vows' in the Bible

"Speak to Aaron, and to his sons, and to all the children of Israel, and say to them, 'Whoever is of the house of Israel, or of the foreigners in Israel, who offers his offering, whether it be any of their vows, or any of their freewill offerings, which they offer to Yahweh for a burnt offering;

besides the Sabbaths of Yahweh, and besides your gifts, and besides all your vows, and besides all your freewill offerings, which you give to Yahweh.