Luke
Luke 3:16ESV·traditional attribution

John answered them all, saying, “I baptize you with water, but he who is mightier than I is coming, the strap of whose sandals I am not worthy to untie. He will baptize you with the Holy Spirit and fire.

Matthew Henry Presbyterian @wholebiblehenry

We are now drawing near to the appearance of our Lord Jesus publicly; the Sun will not be long after the morning-star. We are here told, I. How the people took occasion, from the ministry and baptism of John, to think of the Messiah, and to think of him as at the door, as now come.

Commenting on Luke 3:15-20

John Gill Reformed Baptist @doctorgill

John answered, saying unto them all,.... For some of them might not only so think in their hearts, but express with their mouths the apprehension they had of him; and might put the question to him, as the priests and Levites from Jerusalem afterwards did; or he might know the secret thoughts of their hearts by divine revelation; or be apprized by his disciples of...

Jamieson-Fausset-Brown Reformed @jfbcommentary

John answered--either to the deputation from Jerusalem (see Joh 1:19, &c.), or on some other occasion, simply to remove impressions derogatory to his blessed Master which he knew to be taking hold of the popular mind. (Also see on Mat 3:10.) saying unto them all--in solemn protestation.