John Calvin's Bible Commentary
Jeremiah 51:36
Then follows a clearer explanation, when God promises that he would be the avenger of his chosen people, and that whatever the Jews had suffered would be rendered to Babylon: Therefore thus saith Jehovah, Behold, I will litigate thy quarrel. By this passage we are taught to present our complaints to God, if we wish him to undertake our cause; for when we are silent, he will in his turn rest, as he considers us unworthy of being helped. But if we cry to him, he will doubtless hear us. Then we must remember the order of things, for the Prophet says on the one hand, Let Jerusalem cry, let the daughter of Sion say; and on the other hand he says, Therefore God will come and hear the cry of his people.
He says, first, Behold, I will plead thy cause, and then, I will vindicate or avenge thy vengeance. These are hard words to Latin ears; but yet they contain more force and power than if we were to follow the elegance of the Latin tongue. It is then better to retain the genuine terms than to study neatness too much.
In short, God promises to be the defender of his people, and by using the demonstrative particle, he doubtless removes every doubt, as though the thing was now present. We know that more than seventy years had elapsed since God had spoken thus; for as it has been already stated, it was not after the taking of the city that Jeremiah prophesied against the Chaldeans: but though God suspended his judgment and vengeance for seventy years after the destruction of the city, yet this was said, Behold, I, as though he brought the faithful to witness the event; and this was done for the sake of certainty.
Now, we hence learn, that though God humbles his people, and suffers them even to be overwhelmed with extreme miseries, he will at length become the avenger of all the wrongs which they may have endured; for what has been said of the destruction of the people has a reference to us; nay, what is here said, has not been left on record except for our benefit. And further, let us learn, as I have before reminded you, to prepare our minds for patience whenever God seems to forsake us. Let us, at the same time exercise ourselves constantly in prayer, and God will hear our groans and complaints, and regard our tears.
It is afterwards added, I will make dry her sea; for Babylon, as it has been already stated, was surrounded by the streams of the Euphrates; and there was no easy access to it. The Prophet then compares the fortifications of Babylon to a sea and a fountain. For who would have thought that the Euphrates could be dried up, which is so large a river, and has none equal to it in all Europe? Even the Danube does not come up to the largeness of that river. Who then would have thought it possible that such a river could be made dry, which was like a sea, and its fountain inexhaustible? God then intimates by these words, that such was his power, that all obstacles would vanish away, and that he was resolved at the same time to execute his judgment on the Babylonians. It afterwards follows, —