The Hour will not come until two factions fight one another, with a great slaughter between them, though both make the same claim.
لا تقوم الساعة حتى يقتتل فئتان، فيكون بينهما مقتلة عظيمة دعواهما واحدة.
Bukhari related it in the Book of Virtues (3609), and Muslim in the Book of Tribulations (2888:17), both from the hadith of Abdul-Razzaq, who said, Maamar narrated to us, from Hammam bin Munabbih, who said, this is what Abu Hurairah narrated to us, and then he mentioned it.This prophecy came true through what took place between Ali bin Abu Talib and Muawiya bin Abu Sufyan at Siffin, between Syria and Iraq. His saying, "their claim is one" means their religion is one, and each of them affiliates himself with Islam, and each of them claims that he is upon the truth, so there was a great slaughter between them, just as the Prophet ﷺ had foretold.