John Calvin Commentary Lamentations 2:8

"Jehovah hath purposed to destroy the wall of the daughter of Zion; He hath stretched out the line, he hath not withdrawn his hand from destroying; And he hath made the rampart and wall to lament; they languish together." — Lamentations 2:8 (ASV)

The verb 'to think' has more force than what is commonly assigned to it; for it would be very flat to say that God thought to destroy; but 'to think' here means to resolve or to decree. This is one thing. And then we must bear in mind the contrast between this and those false imaginations by which people are often drawn away, so that they do not believe that God is present in adversities as well as prosperity.

Therefore, as people willfully go astray through various false thoughts, and thus withdraw themselves, as if intentionally, from God, the Prophet says here that the walls of Jerusalem had not fallen by chance, but had been overthrown through a divine decree, because God had so determined. This is according to what we have seen in many places throughout the book of Jeremiah: See, these are the thoughts which God has thought concerning Jerusalem, which He has thought concerning Babylon. The Prophet, then, in these instances, taught what he now confirms here: that when the city Jerusalem was destroyed, it did not happen by chance. Instead, it was because God had brought the Chaldeans there and employed them as His instruments in taking and destroying the city. God, then, has thought to destroy the wall of the daughter of Zion.

It is indeed true that the Chaldeans had actively carried on the war and omitted nothing regarding military skill in order to take the city. But the Prophet here calls the attention of the Jews to a different thought, so that they would acknowledge that they suffered justly for their sins, that God was the chief author of that war, and that the Chaldeans should be viewed as hired soldiers.

He then adds that God had extended a line, or a rule, as is usually done in separating buildings. And then he says, He hath not drawn back His hand from scattering; and so it was, that the ramparts and the walls mourned, and fell down together. We now see that what the Prophet had in view was to lead the Jews fully to believe that the destruction was not to be ascribed to the Chaldeans but, on the contrary, to God.

At the same time, another part of what is taught here must be considered: God would not have been so displeased with the holy city He had chosen, if the people had not extremely provoked Him with their sins.