What should a wife do whose husband married another woman a month after their marriage, then treated her badly and left her, and now wants her back but is lying to her that he will divorce his other wife?

It is not permissible for the husband to mistreat his wife. He must treat her kindly and justly, providing for her and the other wife equally in terms of sustenance and housing. A man's marriage to a second wife is permissible if he is able to be just. A wife's departure to her family's home without her husband's permission, merely because he married another, is considered an act of rebellion (nushuz), and she must repent. It is not permissible for the wife to seek the divorce of the second wife. Patience, piety, and mutual understanding between the spouses are advised for fulfilling their rights. If the wife is harmed, she has the right to seek divorce due to harm, though patience might be better.