This is very narration from Muslim says, when Moawiya bin Abu Sufyan used to appoint a Governor, he used to give orders to his Governors to curse on Imam Ali in mosques and public places. When he appointed Sa’ad bin ABi Waqas he asked for it. Sa,ad bin Abi Waqas said there are three virues of Imam Ali I can not do so, Please read those 3 promonent virtues of Imam Ali in this narration.
This is very well proven fact (unfortunatly) that Moawiya started cursing on Imam Ali in mosques (Friday and Eid sermons), It remained for many decays until the time of Umar bin Abdul Aziz (Ummayad caliph), he stoped it.
This is also a proven reality that along with cursing on Imam Ali (as) Moawiya fought war with Imam Ali, thousands of people got killed. We discussed these things in our articles, we can not talk much in here about Moawiya’s enemity with Imam Ali.
Please read next hadith from Sahih Muslim which is very important.