21:23-27 As our Lord now openly appeared as the Messiah, the chief priests and scribes were much offended, especially because he exposed and removed the abuses they encouraged. Our Lord asked what they thought of John's ministry and baptism. Many are more afraid of the shame of lying than of the sin, and therefore scruple not to speak what they know to be false, as to their own thoughts, affections, and intentions, or their remembering and forgetting. Our Lord refused to answer their inquiry. It is best to shun needless disputes with wicked opposers.

27. And they answered Jesus, and said, We cannot tell—Evidently their difficulty was, how to answer, so as neither to shake their determination to reject the claims of Christ nor damage their reputation with the people. For the truth itself they cared nothing whatever.

Neither tell I you by what authority I do these things—What composure and dignity of wisdom does our Lord here display, as He turns their question upon themselves, and, while revealing His knowledge of their hypocrisy, closes their mouths! Taking advantage of the surprise, silence, and awe produced by this reply, our Lord followed it up immediately by the two following parables.

Parable of the Two Sons (Mt 21:28-32).