Musannaf Ibn Abi Shaybah 32630 — Reports on talk about rulers

It is narrated from Abd al-Rahman bin Abi Layla that a man came to Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) and began to mention what had been revealed in the Qur'an about Abdullah bin Ubayy and to find fault with him. Between the two of them there was also a bond of respect and kinship. Sayyiduna Ka'b (may Allah be pleased with him) listened in silence. After this the man went to Sayyiduna Umar (may Allah be pleased with him) and said: "O Commander of the Believers, let me tell you that I mentioned before Sayyiduna Ka'b what was revealed in the Qur'an about Abdullah bin Ubayy, but he was not affected by it at all." After this Sayyiduna Umar (may Allah be pleased with him) met Sayyiduna Ka'b (may Allah be pleased with him) and said: "I have been told that Abdullah bin Ubayy was mentioned in your presence and you were not affected by it at all?" Sayyiduna Ka'b (may Allah be pleased with him) replied: "I did hear what he said, but when I saw that he deliberately wanted to find fault with me, I considered it improper to help him in finding fault with me." Sayyiduna Umar (may Allah be pleased with him) said: "It would have been good if you had struck him on the nose," or he said: "It would have been good if you had broken his nose."