It was narrated that Abu Barzah said:"Abu Bakr got infuriated with a man, and I said: 'Who is he, O Khalifah of the Messenger of Allah?' He said: 'Why?' I said: 'So that I might strike his neck (killing him) if you tell me to.' He said: 'Would you really do that?' I said: 'Yes. By Allah,' the seriousness of what I said took away his anger. Then he said: 'That is not for anyone after Muhammad [SAW]