Muawiyah cursing Imam Ali (as)

al-Tabari reported: When Muawiyah Ibn Abi Sufyan put al-Mughairah Ibn Shubah in charge of Kufah in Jumada 41 (September 2- October 30, 661), he summoned him. After praising and glorifying God, he said:
"Now then, indeed a forbearing person has been admonished in the past... The wise might do what you want without instruction. Although I have wanted to advise you about many things, I left them alone, trusting in your discernment of what pleases me, what helps my regime and what sets my subjects [raiyyah] on the right path. I would continue to advise you about a quality of yours- do not refrain from abusing Ali and criticizing him, not from asking God's mercy upon Uthman and His forgiveness for him. Continue to shame the companions of Ali, keep at a distance, and don't listen to them. Praise the faction of Uthman, bring them near, and listen to them."
Sunni reference:
History of Tabari, English version, events of year 51 AH,Execution of Hujr Ibn Adi, v18, pp 122-123

http://www.usc.edu/dept/MSA/fundamentals/hadithsunnah/muslim/031.smt.html#031.5915

Book 031, Number 5915:
This hadith has been narrated. on the authority of Shu'ba with the same chain of transmitters. Amir b. Sa'd b. Abi Waqqas reported on the authority of his father that Muawiya b. Abi Sufyin appointed Sa'd as the Governor and said: What prevents you from abusing Abu Turab (Hadrat 'Ali), whereupon be said: It is because of three things which I remember Allah's Messenger (may peace be upon him) having said about him that I would not abuse him and even if I find one of those three things for me, it would be more dear to me than the red camelg. I heard Allah's Messenger (may peace be upon him) say about 'Ali as he left behind hrin in one of his campaigns (that was Tabuk). 'All said to him: Allah's Messenger, you leave me behind along with women and children. Thereupon Allah's Messenger (may peace be upon him) said to him: Aren't you satisfied with being unto me what Aaron was unto Moses but with this exception that there is no prophethood after me. And I (also) heard him say on the Day of Khaibar: I would certainly give this standard to a person who loves Allah and his Messenger and Allah and his Messenger love him too. He (the narrator) said: We have been anxiously waiting for it, when he (the Holy Prophet) said: Call 'Ali. He was called and his eyes were inflamed. He applied saliva to his eyes and handed over the standard to him, and Allah gave him victory. (The third occasion is this) when the (following) verse was revealed:" Let us summon our children and your children." Allah's Messenger (may peace be upon him) called 'Ali, Fitima, Hasan and Husain and said: O Allah, they are my family.