The obligation of making one Kaffarah of Zhihar for all the wives

Q: What is the ruling on a person who pronounces Zhihar (likening his wife to an unmarriageable relative) saying to his wives in a fit of rage during an argument with them: You are all like my mother in marriage. Is this man's saying considered a divorce or he has to offer a Kaffarah (expiation)? If he has to offer a Kaffarah, should he offer a separate Kaffarah for each wife because he has two wives. As he cannot free a Muslim slave in the present time, does he have to offer Kaffarah by fasting. Should he fast four successive months, two months for each wife as a Kaffarah or should he fast two successive months as a Kaffarah for both of them? I hope your Eminence will explain this matter in detail. May Allah reward you with the best.

A: The man who committed Zhihar as mentioned in the question has to offer one Kaffarah of Zhihar for all his wives because he made Zhihar for all of them by one saying. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.