Deuteronomy 24:1-4 NIV
If a man marries a woman who becomes displeasing to him because he finds something indecent about her, and he writes her a certificate of divorce, gives it to her and sends her from his house, and if after she leaves his house she becomes the wife of another man, and her second husband dislikes her and writes her a certificate of divorce, gives it to her and sends her from his house, or if he dies, then her first husband, who divorced her, is not allowed to marry her again after she has been defiled. That would be detestable in the eyes of the LORD. Do not bring sin upon the land the LORD your God is giving you as an inheritance.
NIV: New International Version