Is it permissible for a woman to invoke evil upon her husband and another woman so that they do not marry, and is her attempt to dissuade the woman from marrying him permissible, and is it permissible for her to seek divorce if he marries her? And what is the ruling on one who swears an oath and then breaks it, and is that considered a major sin, and what must she do then?

Firstly: It is permissible for a wife to pray that her husband does not marry her friend if that would be difficult for her, and there is no sin upon her in speaking with her friend with good intentions. Similarly, her prayer that he not marry anyone else is generally permissible. However, it is not permissible to pray for harm or poverty upon him so that he does not marry.

Secondly: It is not permissible for a woman to seek divorce merely because her husband married another. She should be patient, unless patience becomes unbearable for her and she fears that she will not be able to uphold the limits of Allah; in which case, she would be excused in seeking separation.

Thirdly: The ruling on breaking an oath varies between obligation, recommendation, permissibility, prohibition, and dislike, depending on what was sworn upon. If a person breaks their oath, expiation for the oath becomes obligatory upon them by feeding ten poor persons.