Musnad Abu Ya'la al-Mawsili 3:19

Zuhayr narrated to us, Abd al-Rahman ibn Mahdi narrated to us, from Sufyan, from Zubayd, from Sa'd ibn Ubaydah, from Abu Abd al-Rahman, from Ali, from the Prophet (peace and blessings of Allah be upon him), who said: "There is no obedience to any human being in disobedience to Allah."