Musannaf Ibn Abi Shaybah 40651 — reports on Siffin

Hanzalah bin Khuwaylid al-Anazi said: I was sitting with Sayyiduna Muawiyah (may Allah be pleased with him) when two men came to him, each claiming the killing of Sayyiduna Ammar (may Allah be pleased with him). One was saying: "I killed him," and the other was saying: "I killed him." Sayyiduna Abdullah bin Amr (may Allah be pleased with him) said: "Let one of you gladly give it up to the other, for I heard the Messenger of Allah (peace and blessings be upon him) say: 'Ammar will be martyred by a rebellious party.'" On hearing this, Sayyiduna Muawiyah (may Allah be pleased with him) said: "O Amr, will you not keep your madman away from us? Why then are you with us?" He said: "I am with you, but I will not fight. My father complained about me to the Messenger of Allah (peace and blessings be upon him), and he said to me: 'Obey your father as long as he is alive, and do not disobey him.' So I am with you, but I will not fight."