Jerome : (Verse 20). For the tyrant shall be no more, and the scoffer shall cease to be; all those alert to do evil shall be cut off. And there is rejoicing for every downfall: for he who prevailed has fallen. The deceiver, or the arrogant and proud one, is brought to an end, who said: With my strength I will do it, and with my wisdom I will remove the boundaries of nations and destroy their strength; who deceived everyone to such an extent that even the holy one said: My loins are filled with deceits (Psalms 38:8). And all those who kept watch over wickedness have been cut off or destroyed, for their wicked vigilance does not cease: they caused the whole human race to sin by blaspheming the Word of God and placing their mouths in heaven. — Commentary on Isaiah