Treasury of Scripture Knowledge
And this is the testimony John [the Immerser] gave when the Jews sent priests and Levites from Jerusalem to ask him, "Who are you?" [Note: Levites were men who assisted the priests in the Temple service].
There was a man sent from God whose name was John [the Immerser].
These disciples went to John and said to him, "Rabbi, look, that man who was with you on the east side of the Jordan River [i.e., Jesus], whom you testified about, is immersing people and everyone is going to him." [Note: Actually, it was Jesus' disciples who did the immersing. See 4:2].
His coming occurred after John [the Immerser] had preached to Israel that those who repented should be immersed [as evidence that they had done so].