Women wearing Hijab in the presence of the mentally retarded

Q 1: I have a brother who is mentally retarded. In other words, he is not a Mukallaf (person meeting the conditions to be held legally accountable for their actions) subject to the rulings of Shari‘ah (Islamic law), but he helps me by running errands, such as buying things from the market and other similar tasks. (Part No. 17; Page No. 201) He often comes in and out while my wife is at home; what is the obligation in regard to him about this? Should my wife wear a Hijab (veil) in front of him or not? She usually wears a Niqab (face veil), but my brother does see her face.

A: It is not permissible for a man to enter to a non-Mahram woman (not a spouse or an unmarriageable relative), when she is alone in the house, even if the man is mentally retarded. This is due to the Prophet’s saying, “Beware of entering to women” and he (peace be upon him) also said, “No man should be alone with a woman, as Satan is the third of them.” (Reported by Imam Ahmad with an authentic Sanad [chain of narration], on the authority of `Umar ibn Al-Khattab [may Allah be pleased with him]) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.