20:1-8 Men often pretend to examine the evidences of revelation, and the truth of the gospel, when only seeking excuses for their own unbelief and disobedience. Christ answered these priests and scribes with a plain question about the baptism of John, which the common people could answer. They all knew it was from heaven, nothing in it had an earthly tendency. Those that bury the knowledge they have, are justly denied further knowledge. It was just with Christ to refuse to give account of his authority, to those who knew the baptism of John to be from heaven, yet would not believe in him, nor own their knowledge.And they reasoned with themselves,.... Or "they thought with themselves", as the Syriac version; or "within themselves", as the Vulgate Latin, though they did not express it; or "one with another", as the Arabic version; they took counsel together, and debated the matter among themselves, and reasoned after this manner:

saying, if we shall say from heaven; which was what, in their own consciences, they believed to be true,

he will say, why then believed ye him not? in what he said concerning the Messiah; which if they had, as they should, there would have been no reason for such a question they had put; See Gill on Matthew 21:25.