A.T. Robertson Commentary John 3:25

"There arose therefore a questioning on the part of John`s disciples with a Jew about purifying." — John 3:25 (ASV)

A questioning (ζητησις). Old word from ζητεω. See Ac 15:2 for the word where also ζητημα (question) occurs. Ζητησις (process of inquiry) means a meticulous dispute (1 Timothy 6:4).

With a Jew (μετα Ιουδαιου). So correct text, not Ιουδαιων (Jews). Probably some Jew resented John's baptism of Jesus as implying impurity or that they were like Gentiles (cf. proselyte baptism).

About purifying (περ καθαρισμου). See 2:6 for the word. The committee from the Sanhedrin had challenged John's right to baptize (1:25). The Jews had various kinds of baptisms or dippings (Hebrews 6:2), "baptisms of cups and pots and brazen vessels" . The disciples of John came to him with the dispute (the first known baptismal controversy, on the meaning of the ceremony) and with a complaint.