What is the ruling on a husband threatening his ex-wife with depriving her of seeing their daughter if she marries another man, knowing that he divorced her and married another woman, and now wishes to return to her after she has married?

If a divorced woman's iddah (waiting period) has ended, her former husband has no claim over her, and she cannot return to him except with her consent and a new marriage contract. It is not permissible to propose to a woman if there is already an understanding between her and her new suitor, based on the hadith: "A man should not propose marriage when his brother has already proposed, until the first suitor leaves or gives him permission." The custody of the daughter belongs to her mother as long as the mother does not remarry. If she remarries, her right to custody is forfeited. The questioner is advised to leave the woman if her iddah has expired, or to try to marry her through mediation if she is not engaged. Otherwise, he should seek another woman of good religion and character, while fearing Allah concerning the daughter and giving every rightful person their due.