Musnad Ahmad 32:1575

Abu Salamah al-Khuza'i narrated to us, Sulayman ibn Bilal informed us, he said: Rabi'ah ibn Abi 'Abd al-Rahman narrated to me that he heard Anas ibn Malik describing the Prophet, may Allah bless him and grant him peace, as he wished to describe him. He said: Then I heard Anas saying: "The Prophet, may Allah bless him and grant him peace, was of medium stature among the people; he was not short, nor was he excessively tall. He was of a radiant complexion, neither dark-skinned nor starkly white (al-amhaq). His hair was wavy; it was neither straight nor tightly curled. He was sent (as a Prophet) at the age of forty. He stayed in Makkah for ten years and in Madinah for ten years. He passed away at the age of sixty, and there were not twenty white hairs in his head and beard."