“Then said they unto him, Who art thou? that we may give an answer to them that sent us. What sayest thou of thyself?”
King James Version (KJV)
1:20 I am not the Christ - For many supposed he was.
1:21 Art thou Elijah? - He was not that Elijah (the Tishbite) of whom they spoke. Art thou the prophet - Of whom Moses speaks, #Deut 18:15|.
1:23 He said - I am that forerunner of Christ of whom Isaiah speaks. I am the voice - As if he had said, Far from being Christ, or even Elijah, I am nothing but a voice: a sound that so soon as it has expressed the thought of which it is the sign, dies into air, and is known no more. #Isa 40:3|.
1:24 They who were sent were of the Pharisees - Who were peculiarly tenacious of old customs, and jealous of any innovation (except those brought in by their own scribes) unless the innovator had unquestionable proofs of Divine authority.
Joh 1:22,23 Who art thou? When the priests and Levites insisted that John should declare who he was, he quoted Isaiah, and said he was The voice of one crying in the wilderness. See Isa 40:3. See PNT "Mt 3:3". His work was preparation for the Lord.