Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) came to Abdullah bin Muti', who, on seeing him, said: Bring a cushion for Abu Abd al-Rahman. He (may Allah be pleased with him) said: I have not come to sit; I have come to tell you a hadith which I heard from the Prophet (peace and blessings be upon him). He (peace and blessings be upon him) said: "Whoever withdraws his hand from obedience (to the leader) will meet Allah on the Day of Resurrection with no argument (in his defence), and whoever dies without a pledge of allegiance has died the death of jahiliyyah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16612