Muhammad bin Ka'b narrates that Sayyiduna Abdullah bin Unais (may Allah be pleased with him) reports that the Messenger of Allah (peace and blessings be upon him) said: "Who is there who will kill Khalid bin Nubaikh for me?" This man belonged to the tribe of Hudhail and in those days he was residing at the place of 'Urnah, towards 'Arafah. Abdullah bin Unais (may Allah be pleased with him) says: I said, "O Messenger of Allah! I (will kill him), you describe his features (so that I may recognize him)." The Prophet (peace and blessings be upon him) said: "When you see him, you will be frightened." I said, "O Messenger of Allah! By the One Who has sent you with the truth, I have never been frightened by anything (till today)." The narrator says: In any case, Sayyiduna Abdullah bin Unais (may Allah be pleased with him) set out and reached the mountains of 'Arafah before sunset. Abdullah bin Unais (may Allah be pleased with him) says: I met a man there, and when I saw him, I was overawed. When I became frightened of him, I realized that this was the sign which the Messenger of Allah (peace and blessings be upon him) had indicated. He said to me: "Who are you?" I said: "A needy person, is there a place to spend the night?" He said: "Yes, come." I followed him. I quickly performed two rak'ahs of 'Asr prayer, but I kept fearing that he might see me (while I was praying). Then I met him and struck him with the sword and killed him. Then I left from there and went to the Messenger of Allah (peace and blessings be upon him) and informed him of the incident. Muhammad bin Ka'b says: The Messenger of Allah (peace and blessings be upon him) gave him a staff and said: "Keep this staff in your hand until you meet me, and there are few people who hold a staff." Muhammad bin Ka'b says: When Sayyiduna Abdullah bin Unais (may Allah be pleased with him) was about to die, he instructed regarding the staff, so it was placed on his stomach and over his shroud, and then it was buried with him.