Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) said: the Messenger of Allah (peace and blessings be upon him) came out to us and said: "After me there will be rulers over you who will speak words of wisdom on the pulpits, but when they come down (from the pulpits) it (the wisdom) will be snatched from them, and their hearts will be more foul-smelling than carrion. So whoever affirms their lies and helps them in their oppression, he is not from me and I am not from him, and he will not come to the Pond. And whoever does not affirm their lies and does not help them in their oppression, he is from me and I am from him, and he will come to the Pond."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16405