9 In Isaiah we read: "The pride of man shall be brought low; and the Lord alone shall be exalted in that day. And they shall hide the workmanship of their hands in the clefts of the rocks, and in dens and caves of the earth, from fear of the Lord, and from the glory of His power, when He shall arise to shake terribly the earth. For in that day a man shall cast away his idols of gold and silver, which they have made to worship, as useless and hurtful." Perhaps the inquirer himself, who, as Faustus supposes, would laugh and say that he does not believe the Hebrew prophets, has hid idols made with hands in some cleft, or cave, or den. Or he may know a friend, or neighbor, or fellow-citizen who has done this from the fear of the Lord, who by the severe prohibition of the kings of the earth, now serving and bowing down to him, as the prophet predicted, shakes the earth, that is, breaks the stubborn heart of worldly men. The inquirer is not likely to disbelieve the Hebrew prophets, when he finds their predictions fulfilled, perhaps in his own person.
Source: Reply to Faustus the Manichaean (New Advent)