Thomas Aquinas Commentary Lamentations 4:1

"How is the gold become dim! [how] is the most pure gold changed! The stones of the sanctuary are poured out at the head of every street." — Lamentations 4:1 (ASV)

Here, the prophet weeps especially over the misery of the siege. This section is divided into two parts. In the first, he weeps over the misery of the people; in the second, he laments the joy of those who insult them: rejoice, and be glad, O daughter of Edom (Lamentations 4:21).

Regarding the first part, the affliction of the people, the prophet does two things. First, he weeps over their general affliction. Second, he describes their helplessness to resist, as seen in the verse, while we were yet standing, our eyes failed (Lamentations 4:17).

This first point on their general affliction is itself divided into two parts. First, the prophet weeps over the misery of the people in general. Second, he describes it in detail, beginning with, even the sea monsters have drawn out (Lamentations 4:3).

Regarding the misery of the people in general, he again does two things. First, he presents a metaphor (Lamentations 4:1). Second, he explains it, starting with the verse, the noble sons of Zion (Lamentations 4:2).

The Jews were eminent in three things:

1. In the subtlety of their knowledge of God. He has not dealt in this way with every nation, and He has not made His judgments known to them (Psalms 147:20). Therefore, the prophet says, gold. There is gold, and a multitude of jewels: but the lips of knowledge are a precious vessel (Proverbs 20:15). And this gold has become dim through the shame of their unfaithfulness. Therefore my people are gone into captivity, because they have no knowledge (Isaiah 5:13).
2. In their moral beauty. Rich men in virtue, studying beauty: living at peace in their homes . And therefore he says, the finest color, is corrupted, as it were, into the blackness of sin and sorrow. For his face, and the changing of his color .
3. In their religious worship. Therefore, he says, the stones of the sanctuary are scattered in the top of every street, among the various nations. They took away the stones that had been defiled into an unclean place .