Musannaf Ibn Abi Shaybah

Hazrat Yazid bin Bilal says that I participated in the Battle of Siffin on the side of Hazrat Ali (may Allah be pleased with him). Whenever a prisoner was brought to him, he would say, "I will never kill you; the fear of Allah, Lord of the worlds, prevents me." He would take the prisoner's weapon, make him swear that he would not fight against them, and give him four dirhams.