Thomas Aquinas Commentary Lamentations 2:3

"He hath cut off in fierce anger all the horn of Israel; He hath drawn back his right hand from before the enemy: And he hath burned up Jacob like a flaming fire, which devoureth round about." — Lamentations 2:3 (ASV)

Here he shows the impossibility of resisting.

1. He excludes human strength: the horn, that is, power. And I will break all the horns of sinners (Psalms 74:11).
2. He excludes divine help: he has drawn back, as it were, from the defense by which he had previously defended them. Why do you turn away your hand even your right hand? (Psalms 73:11).
3. He concludes by showing the burning of the earth: and he has kindled. He set him on fire, and he understood not (Isaiah 42:25).