What is the ruling of Islamic law regarding a man saying to his wife, "I divorce you if I do such-and-such with you," without doing so, and without intending divorce, considering it a slip of the tongue?

The majority of scholars hold that whoever swears by divorce and then breaks the oath, their divorce takes effect, whether they intended to cause the divorce or merely to threaten and emphasize. This is the fatwa we adopt. However, Sheikh al-Islam Ibn Taymiyyah is of the view that breaking the oath in such a case does not cause the divorce to take effect; rather, an expiation for a broken oath (kaffarat yamin) is due. The oath is broken by not doing what one swore to do within the specified time, or by the expiry of the last possible time if no time was specified. As for uttering it as a slip of the tongue, without intending to utter it at all, the preponderant view is that divorce does not take effect.