Musnad Ahmad 1034:49

Abu ‘Asim narrated to us, Kathir ibn Abi Kathir al-Tamimi narrated to us, Rib’i ibn Hirash narrated to us, and Ishaq ibn Sulayman narrated to us, Kathir narrated to us, from Rib’i, that he came to Hudhayfah ibn al-Yaman in al-Mada’in to visit him and to visit his sister. He said: Hudhayfah said: "What have your people done, O Rib’i? Has anyone among them gone out?" He said: "Yes," and he named some individuals. This was during the time when the people were going out against ‘Uthman. Hudhayfah said: "I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'Whoever departs from the community and holds the leadership in contempt shall meet Allah while having no face before Him.'"