Musnad Ahmad 30:826

Yazid narrated to us, Jarir ibn Hazim narrated to us, from Ghaylan ibn Jarir, from Abu Qays ibn Riyāh, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever exits from obedience and separates from the community, then dies, he dies a death of Jahiliyyah (pre-Islamic ignorance). And whoever fights under a blind banner, becoming angry for his faction, fighting for his faction, and supporting his faction, then is killed, his killing is a killing of Jahiliyyah. And whoever rebels against my Ummah, striking its righteous and its wicked, not sparing its believer, and not fulfilling the covenant of those who have a covenant with it, then he is not of me, and I am not of him."