What is the expiation for a husband tellings his wife mockingly, "You will be divorced," without the intention of divorce?

The statement "you will be divorced" (هتبقي طالق): If you intended it as a promise of divorce, then nothing is binding upon you unless you actually divorce her. However, if you intended to make the divorce contingent upon the fulfillment of a specific request, then divorce occurs according to the majority of scholars, even if you did not intend it. Sheikh al-Islam Ibn Taymiyyah dissented, ruling that only an expiation for a broken oath (kaffarat yamin) is required. In the event that divorce occurs, you may take your wife back before her 'iddah (waiting period) expires if this was the first or second divorce. However, if it was the third, she is not lawful for you until she marries another man and he divorces her after consummating the marriage.