Thomas Aquinas Commentary Lamentations 1:6

"And from the daughter of Zion all her majesty is departed: Her princes are become like harts that find no pasture, And they are gone without strength before the pursuer." — Lamentations 1:6 (ASV)

Here he weeps over the captivity of the adults, and in this regard, he does three things.

1. He describes the loss of ornaments: from the daughter of Zion, that is, of Jerusalem, all her beauty is departed. This refers to the vessels that were taken away, along with the treasures, the princes, and the priests with Jeconiah, the grandson of Josiah (2 Kings 24:12–14).Joachin, the son of Jehoiakim, the son of Josiah. As Thomas Aquinas notes in his commentary on Jeremiah, Joachin is also referred to by the name Jekoniah (Commentary on Jeremiah, ch. 1, lect. 2). As it is written, They shall take away the vessels of your beauty (Ezekiel 16:39).
2. Second, he points to the lack of food: her princes have become like rams that find no pastures, neither for themselves nor for the people. For even bread was lacking in the city when it was besieged in the time of Zedekiah (Jeremiah 34:1–3, 17; 2 Kings 25:1–3). As it is written, Their nobles have perished with famine, and their multitude were dried up with thirst (Isaiah 5:13).
3. Third, he describes the captivity of the princes: and they have gone away without strength, unable to resist, before the face of the pursuer. They were fleeing, as is read in Jeremiah 52:8, where the princes fled into the plains of Jericho. As the psalmist says, my strength has left me (Psalms 37:11).

At the beginning of this verse is the letter vau, which means “and.” This signifies that even these calamities are added by the Lord to the previous ones as vengeance upon us.

And this is the fifth topic of complaint.“The fifth topic is that by using which all disadvantages are brought separately before the eyes of the hearer, so that he who hears of them may seem to see them, and by the very facts themselves, and not only by the description of them, may be moved to pity as if he had been actually present” (Cicero, De inventione 1.55).

Allegorically, the Church is the daughter of the heavenly Zion, after whose pattern she was made. The passage applies to her whenever the beauty of faith departs and her princes—that is, the prelates—fall into various errors. They go before the face of the pursuer, who is the devil or heretics who pervert the faith. These prelates are those that find no pastures in the Scriptures—no pasture of the word of God and of the Lord Jesus Christ.