I was riding along with Muawiya as he returned from Siffin, positioned between him and Amr bin As.Abdullah bin Amr bin As said, "Father, did you not hear the Messenger of Allah ﷺ say to Ammar, 'Alas for you, son of Sumayya! The transgressing party will kill you'?"Amr turned to Muawiya and said, "Do you not hear what this one is saying?"Muawiya replied, "You never stop bringing us this sort of nonsense. Were we the ones who killed him? It was the very people who brought him out who killed him."
حدثنا أبو نعيم عن سفيان عن الأعمش عن عبد الرحمن بن أبي زياد مثله أو نحوه
Its chain of transmission is sahih. Abu Naeem is Fadl bin Dukayn, and Sufyan is Thawri. This hadith has been repeated. Hafiz said in Fath al-Bari 1:452, the hadith "Ammar will be killed by the rebellious faction" has been narrated by a group of companions, among them Qatada bin Numan, as mentioned before, and Umm Salama, narrated by Muslim, and Abu Hurairah, narrated by Tirmidhi, and Abdullah bin Amr bin As, narrated by Nasai, and Yazid in al-Khasais, for it is not found in the smaller Sunan, and it is the hadith of this Musnad, and Uthman bin Affan, and Huzaifa, and Abu Ayub, and Abu Rafi, and Khuzayma bin Thabit, and Muawiya, and Amr bin As, and Abu Yasar, and Ammar himself, all of these narrated by Tabarani and others, and most of their chains are sahih or hasan. It is also narrated from many other companions too numerous to count. In this hadith is one of the signs of prophethood, and a clear virtue for Ali and for Ammar, and a refutation of the Nawasib who claim that Ali was not in the right in his wars.I say, this is a hadith with multiple continuous chains of transmission (mutawatir), there is no doubt about its being mutawatir among the people of knowledge. Praise be to Allah for granting success.