Sahih Muslim | Book 30 | Hadith Number 5780

Narrated by Ibn Sirin
Ibn Sirin reported: I asked Anas b. Malik whether Allah's Messenger (may peace be upon him) dyed his hair. He said: He had not reached the stage when (he needed) dyeing (of his white hair). He had a few white hair in his beard. I said to him: Did Abu Bakr dye his hair? He said: Yes, with hina' (henna).