This is John's testimony, when the Jews sent priests and Levites from Jerusalem to ask him, "Who are you?"
The Sanhedrin, the official religious hierarchy which condemned Jesus to death, was doubtless the body that initiated this inquiry; and why?  The popular report of John's success had reached Jerusalem; and, unthinkably, from their viewpoint he was even teaching that "Jews" needed repentance and baptism!  Were they not the chosen people?  What brand of teaching was this, then, that demanded repentance of Jews?  Also, there had been whispers that this man might be the Messiah; and were not the lords of the Sanhedrin God's chosen instruments for running down and foiling any false Messiah?