The maternal uncle and grandfather as Mahrams

Q: I have some questions that confuse me a great deal. I have asked some learners but found different replies; some are hesitant, and some gave me unsubstantiated answers. 1- Is it permissible for my maternal uncle to marry one of my daughters? If this is not permissible, is he considered a Mahram (unmarriageable relative) to them? 2- Is my maternal grandfather considered a Mahram to my wife? Please give me substantiated answers. May Allah reward you. (Part No. 17; Page No. 356

A: First, it is not permissible for your maternal uncle to marry one of your daughters as he is their uncle. It is permissible for them to be unveiled in his presence and to shake hands with him. Second, it is permissible for your wife to uncover her face in front of your maternal grandfather as he is one of her Mahrams. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.