(2) Tell us, by what authority . . .?--The form of the question is nearly identical in the three Gospels.

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 spoke unto him, saying, tell us by what authority doest thou these things?.... The Arabic and Ethiopic versions read, "this thing"; as if the sanhedrim only referred to his preaching the Gospel, which is mentioned in the preceding verse, and was what he was about when they came to him: but the Persic version reads, "all these things"; not only preaching, but working miracles; and particularly driving the buyers and sellers out of the temple, which especially affected them, they losing their rents thereby:

or who is he that gave thee this authority? God or man? See Gill on Matthew 21:23.