Musannaf Ibn Abi Shaybah

Hazrat Abu Razin narrates that when the government was at Siffin, and the Khawarij left Hazrat Ali (may Allah be pleased with him) and departed from him. The Khawarij were in one army and Hazrat Ali (may Allah be pleased with him) was in another army. When Hazrat Ali (may Allah be pleased with him) returned to Kufa with his army and they (the Khawarij) went to Harura with their army, Hazrat Ali (may Allah be pleased with him) sent Hazrat Ibn Abbas (may Allah be pleased with them both) to them, but he found no leeway. Then Hazrat Ali (may Allah be pleased with him) himself went to talk to them, and there was a conversation, and all became reconciled with each other. And they returned to Kufa. This reconciliation lasted for two or three days. Then Ash'ath bin Qais came, who used to come to Hazrat Ali (may Allah be pleased with him) often, and he said that people are saying that you have reconciled with them despite their disbelief. The next day or on Friday, Hazrat Ali (may Allah be pleased with him) ascended the pulpit, praised Allah Almighty, and in his sermon advised them. He mentioned their separation from the people, commanded them regarding the matter in which they had separated, and Hazrat Ali (may Allah be pleased with him) condemned them and their way. When he descended from the pulpit, voices began to rise from the corners of the mosque, saying: "There is no command except that of Allah!" Hazrat Ali (may Allah be pleased with him) said: "I am waiting for Allah's command regarding you." Then, from the pulpit, he signaled them with his hand to remain silent. Meanwhile, a man from among the Khawarij came, placing his fingers in his ears, reciting this verse: { لَئِنْ أَشْرَکْتَ لَیَحْبَطَنَّ عَمَلُک وَلَتَکُونَنَّ مِنَ الْخَاسِرِینَ }.