Musannaf Ibn Abi Shaybah 40682 — reports on Siffin

Abd al-Aziz bin Rufay' said: When Sayyiduna Ali (may Allah be pleased with him) went to Siffin, he appointed Sayyiduna Abu Mas'ud (may Allah be pleased with him) as governor over the people. He addressed the people on Friday and found them few. So he said: "O people, come out; whoever comes out will be safe. By Allah, we know that some of you dislike this course and find it burdensome. Come out; whoever comes out will find safety. By Allah, we do not regard it as well-being that these two groups should fight and each fear the other. Rather, well-being lies in Allah Almighty setting right the Ummah of Muhammad and uniting them. Shall I not tell you about Sayyiduna Uthman (may Allah be pleased with him) and what people held against him? They did not leave him and his sin until Allah should either punish him or pardon him; and those who wronged him, when they envied him, did not attain what Allah had given him." When Sayyiduna Ali (may Allah be pleased with him) came, he said: "O Farrukh, did you say what I have heard? You are an old man whose intellect has gone." He said: "My mother gave me a better name than the one you have given me. Has my intellect gone, when Paradise has become due for me from Allah and His Messenger? You too know this. And as for what remains of my intellect: we used to say among ourselves that each one who comes later is worse than the one before." When he was at al-Saylahin or al-Qadisiyyah, he came out before the people with water dripping from his hair, and it seemed that he was preparing for Ihram. When he was about to mount his riding animal, people said: "O Abu Mas'ud, give us some advice." He said: "Hold fast to piety and stay with the community of the Muslims, for the community of the Muslims cannot unite upon misguidance." The people asked him again for advice, and he said: "Hold fast to piety and stay with the community of the Muslims; a righteous person attains rest, or rest is obtained from a wicked one."