John Calvin Commentary Lamentations 2:21

"The youth and the old man lie on the ground in the streets; My virgins and my young men are fallen by the sword: Thou hast slain them in the day of thine anger; thou hast slaughtered, [and] not pitied." — Lamentations 2:21 (ASV)

Here he relates, speaking as the Church, another calamity: that the young and the aged were lying prostrate in the streets. He includes children with the old men to show that there was no difference regarding age. Then he says that dead bodies were lying indiscriminately in public places. He adds that virgins and young men had fallen by the sword; by this, he confirms the previous statement, for nothing new is said here; rather, only the manner in which they had been slain is shown, for the young men and young women had been slain by the sword without any distinction. The enemies, at the same time, had not spared the old, even while they killed the very flower of the people.

But the Prophet at the same time shows that all this was to be ascribed to God—not so that the Jews might reason earnestly with Him, but so that they might cease to lament their calamities in vain, and instead turn to God. Therefore, he does not say that the young and the old had been slain by the enemies, but by God Himself.

But it was difficult to convince the Jews of this, for they were so filled with rage against their enemies that they could not turn their thoughts to consider God’s judgments. This, then, is the reason why the Prophet makes God the author of all their calamities; Thou, he says, hast slain in the day of thy wrath; thou hast killed and not spared. And though the people seem here in a way to contend with God, we must still bear in mind the Prophet’s design: to teach the people to look to God Himself, so that they might know that they had to deal with Him. For there ought to be a progression from one truth to another, so that people, conscious of their sins, should first give glory to God and then humbly seek to avert the wrath they have deserved. It then continues—