Musnad Ahmad 1119:12

'Ali ibn Ishaq narrated to us, he said: 'Abdullah informed us, he said: 'Abd al-Rahman ibn Yazid ibn Jabir informed me, he said: Ruzayq, the freed slave of Banu Fazarah, narrated to me, from Muslim ibn Qurazah—and he was the cousin of 'Awf ibn Malik—he said: I heard 'Awf ibn Malik saying: I heard the Messenger of Allah (peace and blessings of Allah be upon him) saying: "The best of your leaders are those whom you love and they love you, and you pray for them and they pray for you. And the worst of your leaders are those whom you hate and they hate you, and you curse them and they curse you." We said: "O Messenger of Allah, shall we not oppose them with the sword at that time?" He said: "No, as long as they establish the prayer among you. Beware, whoever has a ruler appointed over him, and he sees him committing something of the disobedience of Allah, let him disapprove of what he commits of the disobedience of Allah, but let him not withdraw a hand from obedience."