Sufyan bin Abdullah Thaqafi (may Allah be pleased with him) narrates: I said, "O Messenger of Allah (peace be upon him)! Tell me about something which I may hold firmly." The Prophet (peace be upon him) said: "Say: My Lord is Allah, and then remain steadfast." The narrator says: I asked, "O Messenger of Allah (peace be upon him)! What do you fear most for me?" So the Prophet (peace be upon him) held his tongue and said: "This."