Narrated Anas: The Prophet delivered a sermon the like of which I had never heard before. He said, If you but knew what I know then you would have laughed little and wept much. On hearing that, the companions of the Prophet covered their faces and the sound of their weeping was heard. A man said, Who is my father? The Prophet said, So-and-so. So this Verse was revealed: Ask not about things which, if made plain to you, may cause you trouble. (5.101)