John Calvin Commentary Lamentations 4:11

"Jehovah hath accomplished his wrath, he hath poured out his fierce anger; And he hath kindled a fire in Zion, which hath devoured the foundations thereof." — Lamentations 4:11 (ASV)

He finally concludes that nothing was lacking to complete the extreme vengeance of God. For if the Jews had been chastised in an ordinary way, they would have still minimized their sins, as we know that they were not easily led to repentance. Therefore, the Prophet, to show that their offenses had not been minor, but that they had been extremely wicked before God, says that the whole of God’s wrath had been executed: Jehovah has completed his wrath. The expression is indeed harsh to Latin ears, but the meaning is that He had carried out His extreme judgment.

He afterwards adds, He has poured forth the indignation of his wrath. God is indeed content with moderate punishment, provided people are awakened from their lethargy; but when He pours forth His wrath, there is no hope of repentance. It is then a sign of final despair when God’s vengeance overflows like a deluge. But when Jeremiah speaks this way, he does not contend with God, but rather reminds the Jews of what they deserved, as it was stated yesterday. There is, then, no doubt that he argues, from the severity of their punishment, that there was no reason for the Jews to flatter themselves any longer, since God had dealt so severely with them.

He then, in other words, points out the same thing: that God had kindled a fire which devoured or consumed the very foundations. Fire usually takes hold of the roofs of houses, or, when it creeps further, it does not go beyond the surface. It is a very rare thing for it to penetrate into the foundations.

Let us also understand that the Prophet speaks metaphorically of the destruction of the city, for it was such that it left nothing remaining. For when some ruins remain, there is some hint of a future restoration; at least onlookers are inclined to hope that what has fallen will be restored. But when the buildings are not only pulled down, but also demolished from their foundations, then the destruction seems to be without any hope of restoration. And this is what the Prophet means when he says that the fire had consumed, not only what was above ground, but the very foundations of Jerusalem.