Musnad Ahmad 61
It was narrated from Abu Barzah al-Aslami that he said:
We were with Abu Bakr as-Siddeeq when he was conducting some business of caliphate and he got very angry with one of the Muslims. When I saw that I said: O Khaleefah of the Messenger of Allah, shall I strike his neck? When I mentioned killing him, he changed the subject completely, When we parted, Abu Bakr as Siddeeq sent word to me after that and said: O Abu Barzah, what did you say? I said: I have forgotten what I said; remind me. He said: Don't you remember what you said? I said: No, by Allah. He said: Do you remember, when you saw me get angry with that man, you said: Shall I strike his neck, O khaleefah of the Messenger of Allah? Don't you remember that? would you really have done that? I said: Yes, by Allah. If you order me to do it now, I will do it. He said: Woe to you! By Allah, that is not for anyone after Muhammad (ﷺ).
حَدَّثَنَا عَفَّانُ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، حَدَّثَنَا يُونُسُ بْنُ عُبَيْدٍ، عَنْ حُمَيْدِ بْنِ هِلَالٍ، عَنْ عَبْدِ اللَّهِ بْنِ مُطَرِّفِ بْنِ الشِّخِّيرِ، أَنَّهُ حَدَّثَهُمْ عَنْ أَبِي بَرْزَةَ الْأَسْلَمِيِّ، أَنَّهُ قَالَ كُنَّا عِنْدَ أَبِي بَكْرٍ الصِّدِّيقِ رَضِيَ اللَّهُ عَنْهُ فِي عَمَلِهِ فَغَضِبَ عَلَى رَجُلٍ مِنْ الْمُسْلِمِينَ فَاشْتَدَّ غَضَبُهُ عَلَيْهِ جِدًّا فَلَمَّا رَأَيْتُ ذَلِكَ قُلْتُ يَا خَلِيفَةَ رَسُولِ اللَّهِ أَضْرِبُ عُنُقَهُ فَلَمَّا ذَكَرْتُ الْقَتْلَ صَرَفَ عَنْ ذَلِكَ الْحَدِيثِ أَجْمَعَ إِلَى غَيْرِ ذَلِكَ مِنْ النَّحْوِ فَلَمَّا تَفَرَّقْنَا أَرْسَلَ إِلَيَّ بَعْدَ ذَلِكَ أَبُو بَكْرٍ الصِّدِّيقُ رَضِيَ اللَّهُ عَنْهُ فَقَالَ يَا أَبَا بَرْزَةَ مَا قُلْتَ قَالَ وَنَسِيتُ الَّذِي قُلْتُ قُلْتُ ذَكِّرْنِيهِ قَالَ أَمَا تَذْكُرُ مَا قُلْتَ قَالَ قُلْتُ لَا وَاللَّهِ قَالَ أَرَأَيْتَ حِينَ رَأَيْتَنِي غَضِبْتُ عَلَى الرَّجُلِ فَقُلْتَ أَضْرِبُ عُنُقَهُ يَا خَلِيفَةَ رَسُولِ اللَّهِ أَمَا تَذْكُرُ ذَاكَ أَوَكُنْتَ فَاعِلًا ذَاكَ قَالَ قُلْتُ نَعَمْ وَاللَّهِ وَالْآنَ إِنْ أَمَرْتَنِي فَعَلْتُ قَالَ وَيْحَكَ أَوْ وَيْلَكَ إِنَّ تِلْكَ وَاللَّهِ مَا هِيَ لِأَحَدٍ بَعْدَ مُحَمَّدٍ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ‏.‏