Musannaf Ibn Abi Shayba 38:151

Affan narrated to us, he said: Shu'bah narrated to us, from Abu Ishaq, he said: I heard Asim ibn Damrah say: "The Khawarij revolted against the judgment, and they said: 'There is no judgment except for Allah.' Ali said: 'Indeed, there is no judgment except for Allah, but they are saying: "There is no leadership." And there must be a leader for the people, whether righteous or wicked, in whose leadership the believer works, the disbeliever enjoys, and Allah brings the term to its end.'"