Jerome : (Verse 21). Why do people sin in words and overthrow the one who argues at the gate? And they turned away in vain from the just. But the demons, themselves wicked, made all men sin in speech, blaspheming with various teachings, and they would overthrow the one reproaching in the gate and in judgment as much as they could, and they made him turn away from righteousness, who was in the gates of the daughter of Zion, exalted from the gates of death; and he rebuked those who hated him in the gates. These things we understand concerning the devil and his angels, the Nazarenes consider them to be spoken against the scribes and Pharisees, because they failed in their second attempt, who before mocked the people with their wicked traditions; and they watched day and night to deceive the simple, who made men sin against the Word of God, to deny Christ the Son of God. — Commentary on Isaiah