Gregory the Dialogist

Hypocrites and crafty men provoke the wrath of God. When mentioning hypocrites, he appropriately subjoins, 'and crafty.' For unless they are crafty in wit, they cannot consistently make pretence of that which they wish to appear. For there are certain faults, which are easily perpetrated even by those of duller sense. For any one even of dull understanding is able to swell, for instance, with pride, to be eager with the desires of avarice, and to yield to the assaults of lust. …

Morals on the Book of Job, Book XXVI ↗

Thomas Aquinas

Since men sometimes suffer adversities even though their sins are not apparent, he wants to preclude his previously cited opinion being dashed to pieces by this fact. So he interprets them to be pretenders because they make a pretense of justice which they do not have, and are clever inasmuch as they use certain things to do injustice under the guise of justice. In this they sin more gravely. So he says, "Pretenders and knaves provoke the anger of God," since God detests this even more. …

Commentary on Job ↗