About the Kharijites and their opinion on Arbitration
We did not name people the arbitrators but we named the Qur'an the arbitrator. The Qur'an is a book, covered, between two flaps, and it does not speak. It should therefore necessarily have an interpreter. Men alone can be such interpreters.
When these people invited us to name the Qur'an as the arbitrator between us, we could not be the party turning away from the Book of Allah. since Allah has said:
. . . And then if ye quarrel about anything refer it to Allah and the Prophet . . (Qur'an, 4:59)
Reference to Allah means that we decide according to the Qur'an while reference to the Prophet means that we follow his Sunnah. Now therefore, if arbitration were truly done through the Book of Allah (Qur'an). we would be the most rightful of all people for the Caliphate; or if it were done by the Sunnah of the Holy Prophet (PBUH), we would be the most preferable of them.
Concerning your point why I allowed a time lag between myself and them with regard to the Arbitration, I did so in order that the ignorant may find out (the truth) and one who already knows may hold with it firmly.
Possibly Allah may, as a result of this peace, improve the condition of these people, and they will not be caught by the throats and will not, before indication of the right, fall into rebellion as before. Certainly the best man before Allah is he who loves most to act according to right, even though it causes him hardship and grief rather than according to wrong, even though it gives him benefit and increase.
So, where are you being misled and from where have you been brought (to this state)? Be prepared to march to the people who have deviated from the right and do not see it, have been entangled in wrong-doing and are not corrected.
They are away from the Book and turned from the (right) path. You are not trustworthy to rely upon, nor are you holders of honour to be adhered to. You are very bad in kindling the fire of fighting.
Woe to you! I had to bear a lot of worries from you. Some day I call you (to jihad) and some day I speak to you in confidence, you are neither true free men at the time of call, nor trustworthy brothers at the time of speaking in confidence.