Hasan al-Basri (may Allah have mercy on him) said: I asked Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him): The verse of concession was revealed concerning you, so what did you do? He said: "I slaughtered a sheep."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16404
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
It is narrated from Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Fasting is a shield, and charity extinguishes sin just as water extinguishes fire."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16406
It is narrated from Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "O Ka'b bin Ujrah, may Allah protect you from rulers who will come after me. Whoever goes in to them, affirms their lies and helps them in their oppression, he is not from me and I am not from him, and he will never come to the Pond."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16407