Merits of the Helpers in Madinah (Ansaar)

Bukhari :: Book 5 :: Volume 58 :: Hadith 205

Narrated 'Abdullah bin 'Umar:

When 'Umar embraced Islam, all The (disbelieving) people gathered around his home and said, "'Umar has embraced Islam." At that time I was still a boy and was on the roof of my house. There came a man wearing a cloak of Dibaj (i.e. a kind of silk), and said, "Umar has embraced Islam. Nobody can harm him for I am his protector." I then saw the people going away from 'Umar and asked who the man was, and they said, "Al-'As bin Wail."