Musnad Ahmad 1014:5

Hajjaj ibn Nusayr al-Fasatiti narrated to us, and he said: I did not hear from him other than this. He said: Qurrah ibn Khalid narrated to us, from Anas ibn Sirin, Abu Zayd ibn Akhtab narrated to me, he said: The Messenger of Allah, peace and blessings of Allah be upon him, said to me: "May Allah beautify you." Anas said: And he was a beautiful man, with good streaks of gray hair.