Does the father's divorce of the mother take effect if their daughters go to the educational institute after he has forbidden it, knowing that the mother is blameless in this?

The father's divorce of the mother occurs when the questioner and her sister go to the educational institute, whether the father intended to effect the divorce or merely to threaten. This is the view of most scholars. He may take back the mother during her iddah (waiting period) if he has not divorced her more than once before this. Some scholars, like Ibn Taymiyyah, are of the opinion that one who swears an oath of divorce as a threat is only required to pay an expiation for an oath (kaffarat yamin), and the divorce does not occur. It is also important to note that the prescribed oath is to swear by Allah the Almighty, whereas swearing by divorce is among the oaths of the dissolute.