Musnad Abu Ya'la al-Mawsili 3:117

He said: And Zuhayr ibn Harb narrated to us, he said: Abd al-Rahman ibn Mahdi narrated to us, from Sufyan, from Zubayd, from Sa'd ibn 'Ubaydah, from Abu Abd al-Rahman al-Sulami, from Ali, from the Prophet (may Allah bless him and grant him peace), who said: "There is no obedience to anyone in disobedience to Allah."