What is the ruling on a husband saying to his wife: "By divorce, it's not working" - referring to the fan - so if it does work, does the oath take effect, is it considered a divorce, and is expiation required?

The majority of scholars are of the view that if a person swears an oath by divorce and then breaks it, his wife is divorced, whether he intended divorce or merely a threat. However, Sheikh Al-Islam Ibn Taymiyyah holds that an oath of divorce used for threat or emphasis obliges the swearer to pay an expiation for an oath (kaffarat yamin) and does not result in divorce. Our fatwa here follows the opinion of the majority. Therefore, if what the husband swore to deny occurs, a divorce takes place, and he may take his wife back if it is not the third divorce and before the 'iddah (waiting period) expires. As for Ibn Taymiyyah’s view, no divorce occurs, but an expiation for an oath becomes obligatory. It should be noted that the lawful oath is by Allah Almighty, and swearing by divorce is among the oaths of transgressors and may lead to grave consequences.