21. And they shall enter into the clefts of the rocks This repetition is not superfluous, though Isaiah again employs the same words which he had lately used; for what is so difficult as to impress on the minds of men sincere fear of God? Nor is it only in hypocrites that we perceive this, but in ourselves, if we bestow careful attention; for how many things are presented to us by which our minds ought to be deeply affected, and yet we are scarcely moved! More especially, it was necessary that this judgment of God should be earnestly placed before hypocrites, who took delight in wickedness. But now he points out the severity of God’s vengeance by this consideration, that the ungodly choose rather to be swallowed up by the deepest gulfs than to come under the eye of God. This, too, is the passage from which Christ borrowed the threatening which he pronounces on the Jews,
In that day shall they say to the mountains cover us; and to the hills, Hide us. (Luke 23:30.)