When the situation grew intolerable, Hazrat Ali (AS) resolved to snub the defaulters. He summoned the dissenters to submit but they refused to obey him. Before declaring war upon them, he delivered this sermon: “Turn your heart to me. When the army of Moavia hoisted the Holy Quran on their lances, did you not advise me to stop fighting? Did you not tell me to give them protection because they belonged to the same religion? I told you not to be taken in by their treachery. I exhorted you to go on fighting boldly and patiently till the enemy was completely defeated. At that time you unanimously stressed upon me to stop fighting and agree to the appointment of arbitrators. Then we took a promise from the umpires not to deviate from the Holy Quran. They promised not to do so, but they did not abide by their promise. They left the truth deliberately but it was not my fault. Your false estimate has entangled you in this trap. Now you have revolted against me. I warn you to mend your ways otherwise some of you may lie dead in blood and dust in this valley”.
After this, he proclaimed amnesty to all those who would return to camp or keep away from the battle. The majority of the Khawarij with the exception of 1,800 men, took advantage of the declaration. Khirrit, an influential chief, was the leader of the band of dissenters. He preached lawlessness and incited the people against Hazrat (AS). It was an open challenge to the authority of the Caliph who had no alternative but to launch a campaign against the rebels. Thus the most fearful battle was fought and many notorious Khawarij leaders were killed in the Battle of Naharwan. They fought disparately but were utterly destroyed. This defeat, however, did not crush the opposition. The leaders of this movement spread diffusely in every nook and corner of the country and adopted under-hand methods to sow the seeds of division, suspicion, hatred and disobedience. Numerous simple hearted but sincere supporters of Hazrat Ali (AS) were victimized by them.