John Calvin Commentary Jeremiah 21:10

"For I have set my face upon this city for evil, and not for good, saith Jehovah: it shall be given into the hand of the king of Babylon, and he shall burn it with fire." — Jeremiah 21:10 (ASV)

He again confirms what he had said: that it would be the way of death if the Jews remained fixed in the city, for this would be to struggle against God. For God is said to set His face for evil, because He had fully determined to punish that nation. To set the face is the same as to be resolute. Then God says that what He had resolved regarding the destruction of Jerusalem could not be changed. Now, what must ultimately be the outcome when anyone thinks that he can, against the will of God, escape death? Just as those who violently stumble against a stone break their legs, and arms, and head too; so those who furiously stumble against God bring upon themselves final ruin.

We therefore see why the Prophet added this verse: it was so that the Jews might not in their usual manner foster vain hopes, for to hope for any good was to contend with God Himself. Delivered, he says, shall be this city into the hand of the king of Babylon, and he shall burn it with fire. He intimates that Nebuchadnezzar would not only conquer the people and triumph over a captured city, but that the city itself was doomed to destruction. It is, indeed, a most grievous thing when a city is completely demolished: cities are often captured, and the conqueror removes the inhabitants to various places, while it still remains a habitable place; but God declares here that He would act more severely towards the city of Jerusalem, for it was to perish by fire.