AbuBarzah said: I was with AbuBakr. He became angry at a man and uttered hot words. I said: Do you permit me, Caliph of the Messenger of Allah ﷺ, that I cut off his neck? These words of mine removed his anger; he stood and went in. He then sent for me and said: What did you say just now? I said: (I had said:) Permit me that I cut off his neck. He said: Would you do it if I ordered you? I said: Yes. He said: No, I swear by Allah, this is not allowed for any man after Muhammad ﷺ. Abu Dawud said: This is Yazid's version. Ahmad bin Hanbal said: That is, Abu Bakr has no powers to slay a man except for three reasons which the Messenger of Allah ﷺ had mentioned: disbelief after belief, fornication after marriage, or killing a man without (murdering) any man by him. The Prophet ﷺ had powers to kill.  

عَنِ النَّبِيِّ ﷺ ح وَحَدَّثَنَا هَارُونُ بْنُ عَبْدِ اللَّهِ وَنُصَيْرُ بْنُ الْفَرَجِ قَالاَ حَدَّثَنَا أَبُو أُسَامَةَ عَنْ يَزِيدَ بْنِ زُرَيْعٍ عَنْ يُونُسَ بْنِ عُبَيْدٍ عَنْ حُمَيْدِ بْنِ هِلاَلٍ عَنْ عَبْدِ اللَّهِ بْنِ مُطَرِّفٍ عَنْ أَبِي بَرْزَةَ قَالَ كُنْتُ عِنْدَ أَبِي بَكْرٍ ؓ فَتَغَيَّظَ عَلَى رَجُلٍ فَاشْتَدَّ عَلَيْهِ فَقُلْتُ تَأْذَنُ لِي يَا خَلِيفَةَ رَسُولِ اللَّهِ ﷺ أَضْرِبُ عُنُقَهُ قَالَ فَأَذْهَبَتْ كَلِمَتِي غَضَبَهُ فَقَامَ فَدَخَلَ فَأَرْسَلَ إِلَىَّ فَقَالَ مَا الَّذِي قُلْتَ آنِفًا قُلْتُ ائْذَنْ لِي أَضْرِبْ عُنُقَهُ قَالَ أَكُنْتَ فَاعِلاً لَوْ أَمَرْتُكَ قُلْتُ نَعَمْ قَالَ لاَ وَاللَّهِ مَا كَانَتْ لِبَشَرٍ بَعْدَ مُحَمَّدٍ ﷺ