Matthew
Matthew 21:25ESV·traditional attribution

The baptism of John, from where did it come? From heaven or from man?” And they discussed it among themselves, saying, “If we say, ‘From heaven,’ he will say to us, ‘Why then did you not believe him?’

John Calvin Reformed @genevareformer

25 Whence was the baptism of John? Christ interrogates them about the baptism of John, not only to show that they were unworthy of any authority, because they had despised a holy prophet of God, but also to convict them, by their own reply, of having impudently pretended ignorance of a matter with which they were well acquainted.

John Gill Reformed Baptist @doctorgill

The baptism of John, whence was it?.... By the baptism of John, is meant the ordinance of water baptism, which was first administered by him; from whence he took the name of John the Baptist: and the doctrine which he preached concerning it, and previous to it, and even the whole of his ministry; which is denominated from a principal part of it, and which...

Jamieson-Fausset-Brown Reformed @jfbcommentary

The baptism of John--meaning his whole mission and ministry, of which baptism was the proper character. whence was it? from heaven, or of men?--What wisdom there was in this way of meeting their question will best appear by their reply.