Musnad Ahmad 32:1282

'Abd al-Samad narrated to us, Harb ibn Shaddad al-Basri narrated to us, Yahya—meaning Ibn Abi Kathir—narrated to us, and 'Amr ibn Zunayb al-'Anbari said: That Anas ibn Malik narrated to him, that Mu'adh said: "O Messenger of Allah, what do you see if we have leaders who do not follow your Sunnah and do not take by your command, so what do you command regarding them?" The Messenger of Allah (peace and blessings of Allah be upon him) said: "There is no obedience for one who does not obey Allah."