7 But neither will these men be able to maintain that such words were uttered in an ironical manner, since it is proved to them by the words themselves that they were in earnest. For He who uttered them was Truth, and did truly vindicate His own house, by driving out of it the changers of money, who were buying and selling, saying unto them: “It is written, My house shall be called the house of prayer; but you have made it a den of thieves.” And what reason had He for thus doing and saying, and vindicating His house, if He did preach another God?
But [He did so], that He might point out the transgressors of His Father's law; for neither did He bring any accusation against the house, nor did He blame the law, which He had come to fulfil; but He reproved those who were putting His house to an improper use, and those who were transgressing the law. And therefore the scribes and Pharisees, too, who from the times of the law had begun to despise God, did not receive His Word, that is, they did not believe in Christ. Of these Esaias says: “Your princes are rebellious, companions of thieves, loving gifts, following after rewards, not judging the fatherless, and negligent of the cause of the widows.” And Jeremiah, in like manner: “They,” he says, “who rule my people did not know me; they are senseless and imprudent children; they are wise to do evil, but to do well they have no knowledge.”
Source: Adversus haereses (New Advent)