What is the ruling regarding someone who swore an oath of divorce upon his wife that his son would not go to school, and he did not go, so what is the ruling?

Swearing by divorce is considered a conditional divorce. If the event sworn upon occurs, then divorce takes place, according to the majority of jurists. Some jurists, however, hold that if the intention was merely to threaten, then an expiation for breaking an oath (kaffarat yamin (definition)) is required. Since the event sworn upon did not occur, nothing is entailed. And if an oath had a reason which then ceased to exist, nothing is entailed from it either. Spouses should resolve their problems away from pronouncements of divorce.