سنن النسائي

It was narrated from Yunus bin 'Ubaid, from Humaid bin Hilal, from 'Abdullah bin Mutarrif bin Ash-Shikhkhir, from Abu Barzah Al-Aslami, that he said: "We were with Abu Bakr As-Siddiq, and he got angry with a man from among the Muslims, and became very angry indeed. When I saw that, I said: 'O Khalifah of the Messenger of Allah, shall I strike his neck?' When I mentioned killing him, he stopped being angry with him and changed the subject. When we parted, he sent for me and said: 'O Abu Barzah, what did you say?' I said: 'I have forgotten what I said; remind me.' He said: 'Do you not remember what you said?' I said: 'No, by Allah.' He said: 'Don't you remember, when you saw me angry with a man, and said, 'I will strike his neck O Khalifah of the Messenger of Allah?' Don't you remember that? Would you really have done that?' I said: 'Yes, by Allah, and if you tell me to do it now, I will do it.' He said: 'By Allah, that is not for anyone after Muhammad [SAW].'"