Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever abandons obedience to the ruler and separates from the community and dies in that state, dies a death of ignorance. Whoever fights under a blind banner, becomes angry due to tribalism, calls towards tribalism, helps because of tribalism, and is killed, then he also dies a death of ignorance. And whoever comes out against my Ummah, killing the righteous and the wicked alike, does not avoid the believer, and does not fulfill the covenant of those with whom he has a covenant, then he is not from me and I am not from him."

It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever withdraws his hand from obedience (in lawful matters of the ruler), he will meet Allah on the Day of Resurrection in such a state that he will have no proof for himself. And whoever dies without having a pledge of allegiance on his neck, he dies the death of ignorance."

It is narrated from Sayyiduna Jundub bin Abdullah Bajali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever is killed blindly under a banner, where he called for tribalism or helped on the basis of tribalism, then his being killed will be like the killing of the days of ignorance."