Sufyan narrates: We met Ata bin Saib in Makkah, and he informed us: We went to visit Abu Abdur Rahman Salami to inquire about his health, and his servant intended to give him medicine. I stopped him, but he said: Let him do it, because I heard Abdullah bin Mas'ud (may Allah be pleased with him) narrate from the Prophet Muhammad (peace and blessings be upon him): "Allah Almighty has sent down a cure for every disease He has sent down." Sufyan sometimes narrated these words: "He has also sent down its healing." "So whoever knows it, knows it, and whoever does not know it, remains unaware of it."