Jerome

However, you are dragged down to the depths of hell. He who had said through pride, 'I will ascend to heaven, I will be like the Most High,' is dragged not only to the depths of hell, but to the deepest depths of hell. In the Gospel, we read about these outer darknesses, where there is weeping and gnashing of teeth (Luke 13:28).

Commentary on Isaiah ↗

Thomas Aquinas

But yet: here, the frustration of his intention; into the depth of the pit, that is, into the harshest punishments: they spend their days in wealth, and in a moment they go down to hell (Job 21:31).

Commentary on Isaiah ↗

Bonaventure

For as long as vain, transitory, passing good is loved, man is "passing over." And such passing over Wisdom reproves. This passing over is the cause of every evil. In this way Lucifer passed over, to whom it was said: "Down to the nether world you go, to the recesses of the pit!" He was thrown first by sin, then by the judgment. Adam did the same: after he had given up the tree of life, he hid. Indeed, he saw himself denuded of all good habits. Wherefore he was thrown out of Paradise.

Collations on the Hexaemeron, Collation 19 ↗