John 3:25 - Coke's Commentary on the Holy Bible

And the Jews— It should be observed, that the word Jews, in this place and some others, does not mean persons of that nation in general, but of the country of Judea (see John 3:22.), where baptism had just then been administered under the direction of Jesus; and where, as most of John's disciples were of Galilee, it was natural for persons of these two schools, to bring their respective disciples into competition; and that some Jews or men of Judea, baptized under Christ, would, by invidious comparisons, raise the jealousy of some Galileans baptized by John. The Jews called all sorts of ablutions prescribed by their teachers purifications: the subject therefore of this debate was, how Jesus, who had been himself baptized by John, came to re-baptize John's disciples, Acts 19:4-5 that is, assume a greater authority than John, and virtually declare, that his baptism was inefficacious for the purposes of purification. The Baptist's disciples, though they had often heard their master speak on the subject, not understanding the subserviency of his ministry to that of Jesus, were unable to give their antagonists a satisfactory answer, so came and proposed their question to John himself. See the next verse.