Deuteronomy 23:22

Interest may be taken of a stranger and not of a brother, which is the line Exodus 22:25 and Leviticus 25:35-37 draw, and Psalm 15:5 and Ezekiel 18:8 make lending without it a mark of the righteous man. Henry reads the permission toward the stranger as evidence that interest is not oppressive in itself, while Ambrose and the canonists after him took the passage as a bar on lending at interest at all. Vows are voluntary, and verse 22 says outright that it is no sin to make none, though what has gone out of the lips binds once it is spoken, which Ecclesiastes 5:4-5 repeats almost line for line. Numbers 30 sets out the law of vows at length, and Judges 11:30-39 is where one spoken in haste is carried through to its end.