Abu Dawud Book 8, Hadith Number 2703.

Narated By Abdullah ibn Mas’ud : I passed when AbuJahl had fallen as his foot was struck (with the swords). I said: O enemy of Allah, AbuJahl, Allah has disgraced a man who was far away from His mercy. I did not fear him at that moment. He replied: It is most strange that a man has been killed by his people. I struck him with a blunt sword. But it did not work, and then his sword fell down from his hand, I struck him with it until he became dead.