Albert Barnes' Notes on the Whole Bible - John 1:25
Why baptizest thou then ... - Baptism on receiving a proselyte from “paganism” was common before the time of John, but it was not customary to baptize a “Jew.” John had changed the custom. He baptized “all,” and they were desirous of knowing by what authority he made such a change in the religious customs of the nation. They presumed, from the fact that he introduced that change, that he claimed to be a prophet or the Christ. They supposed that no one would attempt it without “pretending,” at... read more
The Pulpit Commentary - John 1:25
And they asked him (put the question), and said to him, Why baptizest thou, then, if thou be not £ the Christ, not Elijah, not the prophet? It would seem that, judging from such expressions as Ezekiel 36:25 , Ezekiel 36:26 and Zechariah 13:1 , the Jews expected some renewal of ceremonial purification on a grand scale at the Messianic appearance, and John's repudiation of every personal rank, which could, according to their view, justify him called for some explanation. read more