Sahih Muslim
The Book Pertaining to the Excellent Qualities of the Holy Prophet (may Peace be upon them) and His Companions (Kitab Al-Fadail)
Book Number: 030 / Hadith Number: 5783
Anas b. Malik did not like that a person should pick out his white hair from his head or beard, and Allah's Messenger (may peace be upon him) did not dye, and there was some whiteness in his hair at his chin, on his temples and very little on his head. This hadith has been narrated on the authority of Muthanna through the same chain of transmitters.