Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Umair bin Ishaq that Hazrat Hamza, in the Battle of Uhud, was fighting in front of the Holy Prophet (peace and blessings be upon him) with two swords and was saying, "I am the lion of God." The narrator says, Hazrat Hamza was moving forward and backward when he stumbled and fell flat on his neck and moved away, and the armor on Hazrat Hamza's stomach came undone. Then an Abyssinian slave saw him and struck him with an arrow or a spear, which passed through him.