Musannaf Ibn Abi Shayba 33:401

Aswad ibn Amir narrated to us, from Hammad ibn Salamah, from Hisham, from his father, that al-Zubayr was sent to Egypt. It was said to him, "Indeed, the plague is in it." He said, "We only came to it for the thrusting (of spears) and the plague."