Hazrat Anas (may Allah be pleased with him) narrated that once the Messenger of Allah (peace and blessings be upon him) delivered such a sermon that I had never heard a sermon like it before. He (peace be upon him) said, "If you knew what I know, you would laugh little and weep much." It is narrated that then the companions (may Allah be pleased with them) of the Prophet (peace and blessings be upon him) covered their faces, and despite their efforts to control themselves, the sound of their weeping could be heard. On this occasion, one companion asked, "Who is my father?" The Prophet (peace and blessings be upon him) replied, "So-and-so." Upon this, the verse was revealed: "Do not ask about such things which, if made plain to you, may cause you trouble."