(19) بَابُ بِرِّ الْوَالِدَيْنِ بَعْدَ مَوْتِهِمَا
Ibn Sirin said, "We were with Abu Hurayra one night and he said, 'O Allah,forgive Abu Hurayra and his mother and whoever asks for forgiveness for bothof them.'" Muhammad said, "We used to ask for forgiveness for them so thatwe would be included in Abu Hurayra's supplication."
Reference: Al-Adab Al-Mufrad 37
In-book reference: Book 1, Hadith 37
English translation: Book 1, Hadith 37