It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that Sayyiduna Muhammad bin Maslamah, Abu Abs bin Jabr and Abbad bin Bishr (may Allah be pleased with them) killed Ka'b bin al-Ashraf (the enemy of Islam). When the Prophet (peace and blessings be upon him) looked at them, he said: "These faces have succeeded and prospered." This hadith has a sahih (authentic) chain of narration, but the two Shaykhs did not record it. However, both of them agreed on recording this hadith narrated from Sayyiduna Jabir (may Allah be pleased with him), that the Prophet (peace and blessings be upon him) said: "Who will take responsibility for putting an end to the evil of Ka'b bin al-Ashraf? For he has greatly harmed Allah and His Messenger." But they did not record it with this complete context.

It is narrated from Sayyiduna Abu Abs bin Jabr (may Allah be pleased with him) that Ka'b bin al-Ashraf used to compose poetry (satirising the Prophet (peace and blessings be upon him)), oppose him (peace and blessings be upon him), and go among the tribe of Ghatafan (to incite people). So the Prophet (peace and blessings be upon him) said: "Who will put an end to the evil of Ibn al-Ashraf? For he has harmed Allah and His Messenger." Muhammad bin Maslamah al-Harithi (may Allah be pleased with him) said: O Messenger of Allah! I am here; would you like me to kill him? The Messenger of Allah (peace and blessings be upon him) remained silent. Then he (peace and blessings be upon him) said: "Go to Sa'd bin Mu'adh and consult him." Muhammad bin Maslamah said: I came to Sa'd bin Mu'adh (may Allah be pleased with him) and mentioned it to him, and he said: Set out for this task with the blessing of Allah, and take with you my nephew al-Harith bin Aws bin Mu'adh, Abbad bin Bishr al-Ashhali, Abu Abs bin Jabr al-Harithi and Abu Na'ilah Silkan bin Waqsh al-Ashhali. Muhammad bin Maslamah said: I met all of them and told them about it, and they all came to me except Silkan. He said: O my brother! In my view your word is true, but I do not want to do this until I speak with the Messenger of Allah (peace and blessings be upon him) face to face. So he mentioned it to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Go with your companions." The narrator said: We set out for him at night until we reached his fortress. About this event Sayyiduna Abbad bin Bishr (may Allah be pleased with him) composed verses in which he described their method and the killing in detail. He said: I called out to him, but he paid no heed to my call / until he came out from his upper chamber. I called him again, and he asked: Who is calling? / I said: It is your (foster) brother, Abbad bin Bishr, and these coats of mail of ours are with you as a pledge; keep them for a month or half a month. He said: These are people who are starving and hungry / although they are not deprived of wealth, rather than being in poverty. Then he came down quickly and gladly / and said to us: You have come for a (great) matter. At that time in our right hands were gleaming, sharp swords / well-tried ones, with which we would lay (the enemy) in the dust and cut (them) to pieces. When he came near, I said to my companion: We will attack him with swords the way a sacrificial animal is slaughtered. Then Muhammad bin Maslamah (may Allah be pleased with him) seized him (by the neck) / and roared at him like a fierce lion. Then he brought his sword down on him with full force / and Abu Abs bin Jabr (may Allah be pleased with him) threw him to the ground. At that time Allah Almighty was our sixth, our Protector and Guardian / who granted us the finest blessing and the most honourable victory. And those noble souls came bringing his head / to whom the guide (of guidance) had come with truth and righteousness.