Talmud do Aggeusza 1:13

Rabban Simeon b. Gamaliel said: Great is peace, for Aaron the [High] Priest was praised only for peace; for he loved peace, pursued peace, greeted with the salutation of peace and responded with it, as it is stated, He walked with Me in peace and uprightness.⁵⁶Mal. 2, 6. It teaches that when he noticed two persons at enmity one with the other, he used to go first to one of them and say to him, ‘Why do you hate So-and-so? He has already come to my house, prostrated himself before me and said to me, “I sinned against So-and-so”. Go and pacify him’. When he left this one, he went to the other and spoke to him similarly, and so made peace, love and friendship between a man and his fellow. What is written subsequently? For he is the messenger of the Lord of hosts.⁵⁷ibid. 7. The text of GRA has been followed. [Cf. above, p. 599.]
R. Joshua said: The prophet is called ‘messenger [of the Lord]’ and the priest⁵⁸So GRA. V and H read ‘a Sage’. is called ‘messenger [of the Lord]’. The prophet is called ‘messenger [of the Lord]’, as it is stated, Then spoke Haggai the Lord’s messenger;⁵⁹Hag. 1, 13. and the priest is called ‘messenger [of the Lord]’, as it is stated, For he is the messenger of the Lord of hosts.⁶⁰Mal. 2, 7. Lest you think that this applies even to a priest who is an ‘am ha-’areẓ, the text declares, And they should seek the law at his mouth.⁶¹ibid.