What is the ruling on a wife refusing to wear gloves at her husband's request? Is the husband sinful if he forgives her for that? And is he obligated to compel her?

A woman covering her hands with gloves is a matter of ijtihad (independent reasoning in Islamic law). A husband may advise his wife to wear them and explain to her that it is the more preferable view. If she does not comply, and there are those who issue fatwas permitting the uncovering of hands, then he is not at fault for forgiving her, and he does not have the right to compel her. However, if he fears fitnah (temptation or discord) from her uncovering her hands, then she must cover them, and he must command her to do so. If she does not comply, she would be disobedient to her Lord and her husband.