Musannaf Ibn Abi Shayba 27:44

Al-Fadl ibn Dukayn narrated to us, from Sufyan, from Abu Hasin, from al-Sha’bi, from ‘Asim al-‘Adawi, from Ka’b ibn ‘Ujrah, who said: The Messenger of Allah (may Allah bless him and grant him peace) came out to us while we were sitting on a leather cushion. He said: "There will be rulers after me. Whoever enters upon them and validates their lies and assists them in their oppression, he is not of me, and I am not of him, and he will not come to the Basin (al-Hawd). And whoever does not validate their lies and does not assist them in their oppression, he is of me, and I am of him, and he will come to the Basin."