Q 6:
Is it permissible for a man to allow his wife to shake hands with his friends when they visit him at home; just shake hands, not sit with them?
A: It is not permissible for him to allow her to shake hands with them if they are not Mahrams (spouse or unmarriageable relative). It is not permissible for her to shake hands with a marriageable person even if her husband allows her to do so because obedience must be in what is good. Shaking hands with a marriageable person is prohibited. As for just initiating greetings, it is permissible if there is no softness in speech and she has to wear Hijab (head cover to the waist). May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.