Shaking hands with the ex-wife's mother

Q 1: I married a woman and then divorced her. Is it permissible for me to shake hands with her mother?

A: It is permissible for an ex-husband of a woman to shake hands with her mother, for a man after contracting marriage with a woman is eternally forbidden to marry her mother. She becomes Mahram for him and he is permitted to shake hands with her. May Allah grant us success. May peace and blessings be upon our Prophet, his family and Companions.