Musannaf Ibn Abi Shaybah 35320 — What protects one from being killed

Humayd bin Hilal (may Allah have mercy on him) reports: Abu al-Aliyah (may Allah have mercy on him) came to me and a companion of mine and said: "Come, both of you, for you are both younger than I am and better at preserving hadith than I am." The narrator said: The two of us set off until we came to Bishr bin Asim al-Laythi (may Allah have mercy on him). Abu al-Aliyah (may Allah have mercy on him) said: "Relate your account to these two." He said that Sayyiduna Uqbah bin Malik al-Laythi (may Allah be pleased with him) said: The Prophet (peace and blessings be upon him) sent out a detachment, and that detachment attacked a people. A man broke away from the people, and a man of the detachment pursued him with a drawn sword. The man who had broken away from the people said: "I am indeed a Muslim." But he did not consider what he said, attacked him and killed him. Then this was reported to the Prophet (peace and blessings be upon him), and the Prophet (peace and blessings be upon him) spoke severely about it. When this news reached the killer, then while the Prophet (peace and blessings be upon him) was delivering a sermon, the killer said: "O Prophet of Allah (peace and blessings be upon him)! By Allah, he said this only to save himself from being killed." The Prophet (peace and blessings be upon him) turned away from him and from the people next to him. The man said this twice, and each time the Prophet (peace and blessings be upon him) turned away from him. He could not restrain himself from saying this a third time. Then the Prophet (peace and blessings be upon him) turned his face towards the man, with signs of displeasure showing plainly on his (peace and blessings be upon him) face, and he (peace and blessings be upon him) said: "Allah has indeed refused me concerning one who kills a believer." He (peace and blessings be upon him) repeated this three times.