Now, 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 which is 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 (to guide). Even the royal kite cannot reach it. It is parallel to the ‘Ayyūq (the star Capella), in height.
May Allāh 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 guard yourself and be watchful, because if you recalcitrate till the people of Allāh (are forced to) rush upon you, then matters will be closed for you and whatever can be accepted from you today will not be accepted then; and that is an end to the matter.
 At the end of the battle of the Khārijites, Mu‘āwiyah wrote a letter to Amīr al-mu’minīn wherein, as usual, he indulged in mud-throwing. In reply, Amīr al-mu’minīn wrote this letter in which he has tried to draw Mu‘āwiyah’s attention to the clear facts about this very battle of the Khārijites, because this battle took place in accordance with the prophecy of the Prophet while Amīr al-mu’minīn himself too had said before the battle that besides the people of Jamal and Ṣiffīn he had to fight against one more group and they were the “deviators” from the religion, namely the Khārijites. The occurrence of this battle and the killing of the man with breasts (Dhu’th-thudayyah) was a clear proof of Amīr al-mu’minīn being in the right. If Mu‘āwiyah had not been obsessed with self-advertisement and lust for conquests, and had not shut his eyes against the right like his forefathers Abū Sufyān and his brother ‘Utbah he would have seen right and come on its path. But compelled by his natural inclination he always evaded right and truth and kept himself blind to those sayings of the Prophet which threw light on Amīr al-mu’minīn’s Imāmate and vicegerency. Because of being with the Prophet in the farewell pilgrimage the Prophet’s saying: “Of whomsoever I am the master, ‘Alī is his master” was not hidden from him, and neither was the Prophet's saying that: “O’ ‘Alī you are to me as Hārūn was to Mūsā,” because of his presence on the occasion of the battle of Tabūk. In spite of all this, he passed his life in concealing right and encouraging wrong. This was not due to any misunderstanding but it was his lust for power that kept prompting him to suppress and trample truth and justice.