After his death...
After his death, a man called Zirar, who was a companion of his, met Mu'awiyyah who asked him to describe Ali, peace be upon him, for him. Zirar narrated something he had witnessed about Ali, peace be upon him. He said, "One night I saw him in his special worshipping place of worship.' He was twisting with the fear of God like a man bitten by a snake and weeping with deep sorrow and saying, 'Oh, for the fire of hell'"; Mu'awiyyah wept on hearing this.
Before Ali's death, Mu'awiyyah met Adass bin Hatam and intended to provoke him against Ali, peace be upon him, so he asked him about his three sons who had been killed fighting for Ali, peace be upon him. He wished to hear Adass blame Ali, peace be upon him and so he said, "Was it fair of him to…