Nahj al-Balagha (Peak of Eloquence)

To Mu‘āwiyah, soon after Amīr al-mu’minīn was sworn in. (Muḥammad ibn ‘Umar) al-Wāqidī has mentioned this in his “Kitāb al-Jamal” From the servant of Allāh, ‘Alī Amīr al-mu’minīn to Mu‘āwiyah son of Abū Sufyān : Now, you are aware of my excuses before you people and my shunning you till that happened which was inevitable and which could not be prevented. The story is long and much is to be said. What was to pass has passed and what was to come has come. Therefore, secure (my) allegiance from those who are with you and come in a deputation of your people to me; and that is an end to the matter.