Merits of the Helpers in Madinah (Ansaar)
Bukhari :: Book 5 :: Volume 58 :: Hadith 242
Narrated Ibn Abbas:
Allah's Apostle started receiving the Divine Inspiration at the age of forty. Then he stayed in Mecca for thirteen years, receiving the Divine Revelation. Then he was ordered to migrate and he lived as an Emigrant for ten years and then died at the age of sixty-three (years).