Is a divorce valid if the husband says: "Divorce upon me, it's either me or the heater in the house"?

The fatwa we follow states that divorce occurs by an oath of divorce upon breaking the oath, whether the intention was to effect divorce, to threaten, to prevent, to encourage, or to emphasize. This is the view of the majority of scholars. The reference for determining what was sworn upon is the intention of the swearer. Therefore, if you disobeyed your husband in what he swore an oath upon, according to his intention, then the divorce has occurred. If it was the first or second divorce, he may take you back as long as you are within your iddah (waiting period). However, if it was the third, then you are irrevocably divorced from him (baynunah kubra), and you are not permissible for him until after you marry another man.

As for the view of Sheikh al-Islam Ibn Taymiyyah, if the husband did not intend to effect divorce, but rather intended emphasis or prevention, then if you disobeyed him, divorce does not occur. Instead, he is obligated to pay the expiation for an oath (kaffarat yamin).

The husband is advised to refrain from swearing by divorce.