Musnad Ahmad 652:7

Muhammad ibn Yazid narrated to us, from al-Awwam, who said: A man from the Ansar, from the family of al-Nu’man ibn Bashir, narrated to me, from al-Nu’man ibn Bashir, who said: The Messenger of Allah (peace and blessings of Allah be upon him) came out to us while we were in the mosque after the night prayer (Isha). He raised his gaze toward the sky, then lowered it until we thought that something had occurred in the sky. He said: "Behold, there will be after me rulers who lie and commit injustice. Whoever believes their lies and supports them in their injustice, he is not of me, and I am not of him. And whoever does not believe their lies and does not support them in their injustice, he is of me, and I am of him. Behold, the blood of a Muslim is its own expiation. Behold, 'Glory be to Allah' (Subhan Allah), 'Praise be to Allah' (Al-hamdu lillah), 'There is no god but Allah' (La ilaha illa Allah), and 'Allah is the Greatest' (Allahu Akbar) are the enduring righteous deeds."