Ruling on uncovering the face before the husband's grandfather

Question:
The sister Umm Firas from al-Kharj says: Honorable Shaykh, is my husband's grandfather, whether on his father's side or his mother's side, a mahram (a relative one may not marry)? In other words, may I uncover my face in their presence or not?

Answer:
Yes. All the fathers of my wife, whether on the father's side or the mother's side, and their grandfathers and the grandfathers of their grandfathers, are all mahram (relatives one may not marry) to you, because you are the wife of their son. When Allah, Mighty and Majestic, mentioned the mahram (relatives one may not marry), He said: Therefore, she is a mahram (relative one may not marry) to the father and the grandfather, whether on the mother's side or the father's side, whether near or distant.

The presenter:
May Allah reward you with good, Honorable Shaykh,