Deuteronomy 21:14

And it shall be, if thou have no delight in her, after the marriage had thus taken place, then thou shalt let her go whither she will, as a free woman, with the rights of an Israelitess; but thou shalt not sell her at all for money, such a procedure was not to be thought of, thou shalt not make merchandise of her, not attempt a violent treatment of her by selling her as a slave, because thou hast humbled her, in making use of the right of a husband. This was a humane, merciful provision, intended to protect the dignity of the woman and the sanctity of marriage.