you will never find honour and dignity. Stay away in the same way that the tyrants have gone away!"(144)
The rioters, who were unable to find an answer, began to abuse him and whipped his horse. The dispute became more violent and al-Ashtar used sharp words. Then Imam ordered him to be quiet. They became silent. al-Ashtar turned to the Imam and said: "Give me to leave to attack them and vanquish all of them!" Those present protested, and Imam 'Ali at last agreed to arbitration in accordance with the verdict of the Qur'an.
al-Ashtar said: "If he agrees to this, I, too, am satisfied."
The clamor rose from every side: "the commander of the faithful has agreed! He has agreed!"
Imam had retreated in deeper ponder remained silent, not uttering a word.(145)

Abu Musa and 'Amr ibn al-'As

You are like a dog which on being attacked, breathes hard with its tongue hanging out, and in being left alone, it does the same thing.
Abu Musa addressing 'Amr ibn al-'As
You are like a donkey laden with books.
'Amr ibn al-'As addressing Abu Musa

As we saw, the Imam was eventually compelled to accept the view of the rebels of his army who demanded arbitration. The matter led to the choice of arbitrators. The people of ash-Shim chose 'Amr ibn al-'As, and al-Ash'ath and his Kufan supporters, who after this event formed the party of Khawarij (namely outsiders, leaving 'Ali's side as a successor to the caliphate), declared that Abu Musa was their nominee. The Imam said: "I do not think Abu Musa is the right man for such an important task."
al-Ash'ath and his supporters said: "We choose no one but him, since it was he who warned us against this war from the beginning."
The Imam said: "I could not be pleased with him and his