Letter 65
To Muawiya
This is the time that you should derive benefit by observing a clear view of the main matters, because you have been treading in the path of your forefathers in making wrong claims, spreading false and untrue notions, claiming for yourself what is far above you and demanding what is not meant for you, because you want to run away from right and to revolt against what is more fastened to your flesh and blood namely what has been heard by the depth of your ears and has filled your chest. And after forsaking right there remains nothing except clear misguidance, and after disregarding a (clear) statement there is nothing except confusion. You should therefore guard (yourself) against doubts and its ill-effects of confusion, because for a long time mischief has spread its veils and its gloom has blinded your eyes.
I have received your letter full of uncouth utterances which weaken the cause of peace and nonsensical expressions which have not been prepared with knowledge and forbearance. By reason of these things you have become like one who is sinking in a marsh or groping in a dark place. You have raised yourself to a position which is difficult to approach and devoid of any signs . Even the royal kite cannot reach it. It is parallel to the Ayyuq (star Capella), in height.
May Allah forbid that you be in charge of people's affairs after my assuming authority as Caliph, or that I issue an edict or document granting you authority over any one of them. Therefore, from now onwards you guard yourself and be watchful, because if you oppose till the people of Allah rush upon you, then matters will be closed for you and whatever can be accepted from you today will not be accepted then.