Is it permissible for a non-mahram man to lower a woman into her grave in the presence of her mahrams?

The basic principle is that a woman's mahram relatives are the most deserving of lowering her into her grave, according to Ibn Qudamah and Al-Khallal's narration from Umar (may Allah be pleased with him). If they are not present, or if they are present but there is an impediment preventing them, then it is permissible for a non-relative to lower her, based on what Al-Bukhari narrated from Anas, that the Prophet (peace and blessings be upon him) commanded Abu Talha to lower his daughter into her grave. It is preferable for one who has not had intercourse with his wife that night, as Al-Shawkani stated. Ibn Uthaymeen held the view that any man may lower a woman into her grave, but the most preferable is one of her mahram relatives, or one who has been furthest from marital intimacy.