He said...
In the note he urged them to set out to battle against Imam al-Hasan and commanded them to join him in the best way and most complete readiness. This is the text of the note: “From the servant of Allah, Mu’awiya, the Commander of the faithful, To so-and-so, son of so-and-so, and the Muslims. Salamun ‘alaykum, I thank on your behalf Allah Whom there is no god other than. Praise belongs to Allah, Who sufficed you the burden of your enemy and his killing your caliph.
Most surely Allah through His mercy enabled a man from among His servants to kill Ali bin Abi Talib. He killed him and left his companions in division and disagreement. The letters of their noble men and their leaders have come to us asking for security for themselves and their tribes. Therefore, when this letter of mine reaches you, come to me along with your efforts, fighters, and good equipment.
Certainly, through thanking Allah, you have hit the vengeance and reached the hope; and Allah has destroyed the men of error and aggression; and peace, Allah’s mercy and blessings be on you.”[^1] When this letter reached his leaders and his governors, they provoked the people and urged them to set out and to get ready to battle against Imam al-Hasan, the Prophet’s darling and grandson. Shortly after that Mu’awiya was joined by huge, organized troops supplied with weapons and equipment.
When Mu’awiya had huge troops from among the fighters and those ambitious who yield to nothing except wealth and pleasures, he took them and set off towards Iraq. He himself was the commander-in-chief. He appointed al-Dahhak bin Qays al-Fihri as a governor over his capital. The troops with him were about sixty thousand men, and it was said more. Anyway, the troops obeyed Mu’awiya, and carried out his commands and wishes. They submitted to him. They did not oppose him nor did they disobey him.
Mu’awiya and his army covered the desert. When they arrived at the Bridge of Manbaj,[^2] they stayed there. There he made his affair firm, that he might overcome the events. [^1] Ibn Abi al-Hadeed, Sharh Nahj al-Balagha, vol. 4, p. 13.