By Allāh,  Mu‘āwiyah is not more cunning than I am, but he deceives and commits evil deeds. Had it not been for the reprehensibility of deceit, I would have been the most cunning of all men. But (the fact is that) every deceit is a sin and every sin is disobedience (of Allāh), and every deceitful person will have a banner by which he will be recognised on the Day of Judgement. By Allāh, I cannot be made forgetful by strategy, nor can I be overpowered by hardships.
 People who are ignorant of religion and ethics free from the shackles of religious law and unaware of the conception of punishment and reward find no paucity of excuses and means for the achievement of their objects. They can find ways of success at every stage; but when the dictates of humanity, or Islam, or the limitations imposed by ethics and religious law act as impediments, the chances of devising and finding means become narrow, and the possibility of action becomes restricted. Mu‘āwiyah’s influence and control was the result of these devices and ways in following which he knew no impediment nor any obstacle of what is lawful or unlawful, nor did fear of the Day of Judgement prevent him from acting fearlessly. As al-‘Allāmah ar-Rāghib al-Iṣfahānī while taking account of his characters writes:
“His aim always was to achieve his object whether lawful or unlawful. He did not care for religion nor did he ever think of divine chastisement. Thus, in order to maintain his power he resorted to mis-statements and concoctions, practised all sorts of deceits and contrivances. When he saw that success was not possible without entangling Amīr al-mu’minīn in war he roused Ṭalḥah and az-Zubayr against him. When success could not be achieved by this means he instigated the Syrians and brought about the civil war of Ṣiffīn. And when his rebellions’ position had become known by the killing of ‘Ammār, he at once duped the people by saying that ‘Alī was responsible for killing him as he had brought him into the battlefield; and on another occasion he interpreted the words ‘rebellions party’ occurring in the saying of the Prophet to mean ‘avenging party’ intending to prove that ‘Ammār would be killed by the group that would seek revenge of ‘Uthmān’s blood, although the next portion of this saying namely ‘he will call them towards Paradise while they will call him to Hell,’ does not leave any scope for interpretation. When there was no hope of victory even by these cunning means, he contrived to raise the Qur’ān on spears, although in his view neither the Qur’ān nor its commandments carried any weight. If he had really aimed at a decision by the Qur’ān, he should have put this demand before the commencement of the battle, and when it became known to him that the decision had been secured by ‘Amr ibn al-‘Āṣ by deceiving Abū Mūsā al-Ash‘arī, and that it did not have even a remote connection with the Qur’ān, he should not have accepted it and should have punished ‘Amr ibn al-‘Āṣ for this cunning, or at least should have warned and rebuked him. But on the contrary, his performance was much appreciated and in reward he was made the Governor of Egypt.”
In contrast to this Amīr al-mu’minīn’s conduct was a high specimen of religious law and ethics. He kept in view the requirements of truth and righteousness even in adverse circumstances and did not allow his chaste life to be tarnished by the views of deceit and contrivance. If he wished he could face cunning by cunning, and Mu‘āwiyah’s shameful activities could have been answered by similar activities. For example, when he put a guard on the Euphrates and stopped the supply of its water (to Amīr al-mu’minīn’s men), then the supply of water could have been cut from them also on the grounds that since they had occupied the Euphrates it was lawful to retaliate, and in this way they could be overpowered by weakening their fighting power. But Amīr al-mu’minīn could never tarnish his hands with such an inhuman act which was not permitted by any law or code of ethics, although common people regard such acts against the enemy as lawful and call this duplicity of character for achievement of success, a stroke of policy and administrative ability. But Amīr al-mu’minīn could never think of strengthening his power by fraud or duplicity of behaviour on any occasion. Thus when people advised him to retain the officers of the days of ‘Uthmān in their positions and to befriend Ṭalḥah and az-Zubayr by assigning them governorship of Kūfah and Baṣrah, and make use of Mu‘āwiyah’s ability in administration by giving him the government of Syria, Amīr al-mu’minīn rejected the advice and preferred the commandments of religious law over worldly expendiency, and openly declared about Mu‘āwiyah as follows:
If I allow Mu‘āwiyah to retain what he already has I would be one “who taketh those who lead (people) astray, as helpers” (Qur’ān, 18:51). Those who look at apparent successes do not care to find out by what means the success has been achieved. They support anyone whom they see succeeding by means of cunning ways and deceitful means and begin to regard him an administrator, intelligent, a politician, intellectually brilliant and so on, while he who does not deploy cunning and fraudulent methods owing to his adherance to Islamic commandments and divine instructions and prefers failure to success secured through wrong methods is regarded as ignorant of politics and weak in foresight. They do not feel it necessary to think what difficulties and impediments exist in the way of a person who adheres to principles and laws which prevent him from proceeding forward even after approaching near success.