Sunan Abi Dawud Book 35, Hadith 49
My father said to him (the Prophet): Show me what is on your back, for I am a physician. He (the Prophet) said: You are only a soother. Its physician is He Who has created it.
I went with my father to the Prophet (ﷺ). He had locks hanging down as far as the lobes of the ears stained with henna, and he was wearing two green garments.
I and my father came to the Prophet (ﷺ). He said to a man or to my father: Who is this? He replied: He is my son. He said: Do not commit a crime on him. He had stained his beard with henna.