John Calvin Commentary Jeremiah 50:18

"Therefore thus saith Jehovah of hosts, the God of Israel: Behold, I will punish the king of Babylon and his land, as I have punished the king of Assyria." — Jeremiah 50:18 (ASV)

From what I have said, we may infer with greater certainty that the comparison God employed was intended for this purpose: by portraying Himself as one in sorrow, He might, so to speak, visibly demonstrate His sympathy to them. He then shows that He would be the avenger of the cruelty the Chaldeans had committed, just as He had already been the avenger of all the evils the Assyrians had inflicted on His people.

We must keep in mind the historical context, as the meaning of this passage depends on it. The Assyrians were stronger than the Chaldeans when they harassed the kingdom of Israel. We know, for instance, that in the time of Hezekiah, the king of Babylon sent envoys to him to seek his favor and to entice him into an alliance.

So, while the Assyrian monarchy was formidable, the Assyrians were very hostile to the Israelites and also to the Jews. What followed? Nineveh was overthrown, and Babylon rose to power in its place. Consequently, those who had once ruled were forced to bear the yoke, and in this way Babylon subjugated the Assyrians.

God now refers to this judgment, an event known to everyone. Indeed, the Assyrians themselves did not believe that the God of Israel was the avenger of His people, yet this was true.

Therefore, God here declares that He had already given clear proof of His concern for the welfare of His people. Just as He had punished Assyria, He now declares that He would also take vengeance on the Babylonians.

In this way, by providing an example, He confirms what might have seemed incredible. For who could have imagined that such a powerful monarchy could fall so suddenly? And yet, it happened in a way that surpassed all expectations.

God recounts what had already occurred so that the faithful might be assured that the same judgment the Assyrians had experienced also awaited the Babylonians. This is the straightforward meaning of the Prophet.