Patristic Wisdom: Looking to the Second Sunday in Advent

“Behold, I send My messenger, and he will prepare the way before Me. And the Lord, whom you seek, will suddenly come into His temple, even the Messenger of the covenant, whom you desire. Behold, He is coming,” says the Lord Almighty. But who can endure the day of His coming? And who can withstand His appearance? For He enters like a refiner’s fire and as soap in one’s wash. He will sit as a refiner and a purifier of silver and gold. He will purify the sons of Levi and pour them out as purified gold and silver, and they will bring an offering to the Lord in righteousness.” (Malachi 3:1–3 LXX)

“I for my part shall come,” He is saying, “whom you look to as punisher of sins. There will be present also the angel who ministers to the agreements I have often made with you. When you seek him, you will find him punishing the transgression of your agreements with me.” While the prophet said this as a consequence of what preceded, it is not surprising that the same verse was cited at the coming of blessed John the Baptist, the statement being fulfilled in actual fact by the coming of blessed John as predetermined forerunner and minister, and by the emergence of Christ the Lord, who came at the same time as he and was testified to by him and in whom the salvation of all people was destined to be achieved.

Theodore of Mopsuestia, Commentary on Malachi 3.1