Musnad Abu Ya'la al-Mawsili 1:78

Hashim ibn al-Harith narrated to us, Ubayd Allah ibn Amr narrated to us, from Zayd ibn Abi Unaysah, from Amr ibn Murrah, from Abu Nasr, from Abu Barzah al-Aslami, who said: Abu Bakr became intensely angry at a man, such that he had not been seen more angry than he was on that day. Abu Barzah said to him, "O Caliph of the Messenger of Allah, command me and I will strike his neck." He said: It was as if it were a fire that had been extinguished. He said: Abu Barzah went out, then he sent for him and said, "May your mother be bereaved of you! What did you say?" He replied, "I said: By Allah, if you had commanded me to kill him, I would have killed him." He said, "May your mother be bereaved of you, O Abu Barzah! It (the authority to kill) was not for anyone after the Messenger of Allah, may Allah bless him and grant him peace."