Abd al-Rahman bin Abdullah bin Ka'b (may Allah have mercy on him) says that the group whom the Prophet (peace and blessings be upon him) had sent to Ibn Abi al-Huqayq to kill him killed him and came to the Prophet (peace and blessings be upon him) while he (peace and blessings be upon him) was delivering the sermon on the pulpit on Friday. When the Prophet (peace and blessings be upon him) saw them, he said: 'Aflahat al-wujuh' "The faces have succeeded." They said: "O Messenger of Allah! Glad tidings to you." He (peace and blessings be upon him) asked: "Did you kill him?" They replied: "Yes." He (peace and blessings be upon him) called for the sword with which he had been killed, while he (peace and blessings be upon him) was still on the pulpit. He (peace and blessings be upon him) drew it and said: 'Ajal, hadha ta'amuhu fi dhubab al-sayf' "Yes, this is his food on the edge of the sword." In the group were Abdullah bin Atik and Abdullah bin Unays (may Allah be pleased with them both), Aswad bin Khuza'i (may Allah be pleased with him) (who was their ally), and also Abu Qatadah (may Allah be pleased with him), according to the opinion of al-Zuhri (may Allah have mercy on him), but al-Zuhri (may Allah have mercy on him) did not remember the name of the fifth.
Although this is mursal (with a missing link in its chain), it is a good mursal.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5840