Musnad Ahmad 26:275

Aswad ibn Amir narrated to us, Sharik narrated to us, from Abu Ishaq, from Abu Ubaydah, from his father, who said: I came to Abu Jahl while he was wounded and his leg had been severed. He said: I began striking him with my sword, but it did not have any effect on him—it was said to Sharik regarding the hadith: "Was he defending himself with his sword?" He said: "Yes"—he said: I did not cease until I took his sword and struck him with it until I killed him. He said: Then I came to the Prophet, peace and blessings of Allah be upon him, and said: "Abu Jahl has been killed"—and perhaps Sharik said: "I have killed Abu Jahl." He said: "Did you see him?" I said: "Yes." He said: "By Allah?" twice. I said: "Yes." He said: "Go, so that I may look at him." He went, and he came to him, and the sun had altered him somewhat. He ordered him and his companions, and they were dragged until they were cast into the pit (al-Qalib). He said: And he followed the people of the pit with a curse, and he said: "This was the Pharaoh of this nation."