He sent an answer back to `Ali that if he were to give his...
He sent an answer back to `Ali that if he were to give his permission for a few moments more the battle would be finished and the enemy destroyed. But the Khawarij drew their swords and threatened to hack 'Ali to pieces unless he called him back. Then again word was sent to him that if he wanted to see `Ali alive, he should stop the battle and come back. He returned, and the enemies were jubilant that their stratagem had proved efficacious.
The fighting stopped so that they could leave arbitration to the Qur'an. An arbitration committee was set up, and arbitrators selected from the two sides to rule on the basis of what was agreed on by both sides in the Qur'an and sunnah and to bring an end to hostilities; or else they would add another difference to the already existing differences and cause the situation to deteriorate. 'Ali said that they should choose their arbitrator, and then he would detail his own.
Without the slightest dispute, they unanimously chose `Amr ibn al-`As, the deviser of the stratagem. 'Ali proposed `Abdullah ibn al-`Abbas, who was versed in politics, or Malik al-Ashtar, a self-sacrificing, clear sighted man of faith, or else someone like them. But those fools were looking for someone of their own kind, and they chose a man of the like of Abu Musa al-Ash'ari, a man of no perspicacity who was not on good terms with 'Ali.
However much 'Ali and his friends sought to enlighten these people that Abu Musa was not the man for the job and that such an appointment was not suitable for him, they said that they would not agree to anyone else. Then he said that since things had got to that point, they should do whatever they wanted. So, in the end, they chose this Abu Musa as the arbitrator from the side of 'Ali and his companions.
After months of consultation, `Amr ibn al-`As said to Abu Musa that it would be better for the interests of the Muslims if neither 'Ali nor Mu'awiyah were caliph, that they should choose a third one, and that there was no one else they could choose but `Abdullah ibn `Umar, Abu Musa's son-in-law. Abu Musa said that that was right and asked what they should do. `Amr ibn al-`As said: "You should remove 'Ali from the caliphate, and I will do the same with Mu'awiyah.
Then the Muslims will go and elect a worthy person who will surely be `Abdullah ibn `Umar. Thus the roots of sedition will be destroyed." They terminated on this matter and announced that the people should gather together to listen to their conclusions.