Merits of the Helpers in Madinah (Ansaar)

Bukhari :: Book 5 :: Volume 58 :: Hadith 190

Narrated Ibn 'Abbas:

Allah's Apostle was inspired Divinely at the age of forty. Then he stayed in Mecca for thirteen years, and then was ordered to migrate, and he migrated to Medina and stayed there for ten years and then died.