19 And this is the record of John, when the Jews sent priests and Levites from Jerusalem to ask him, Who art thou?

[And this is the record of John] John the Baptist persisted in this assertion, testifying to the Jews that this Jesus was the Christ.

20 And he confessed, and denied not; but confessed, I am not the Christ.

[I am not the Christ] John renounces himself that Jesus may be all in all. Though God had highly honored him and favored him with particular influence in the discharge of his work, yet he takes care to direct the attention of the people to him alone who is the true Messiah.

21 And they asked him, What then? Art thou Elias? And he saith, I am not. Art thou that prophet? And he answered, No.

[Art thou Elias?] The scribes themselves had taught that Elijah was to come before the Messiah, and this belief of theirs was supported by a literal construction of Malachi 4:5.

[Art thou that prophet?] The prophet spoken of by Moses in Deuteronomy 18:15,18. This text they had also misunderstood, for the prophet or teacher promised by Moses was none other than the Messiah himself. See Acts 3:22-26. The Jews had a tradition that Jeremiah was to return to life and restore the pot of manna, the ark of the covenant and so on which he had hidden so that the Babylonians might not get them.

[I am not] I am not the prophet which you expect, nor Elijah; though he was the Elijah that was to come; for in the spirit and power of that eminent prophet he came, proclaiming the necessity of reformation in Israel. See Matthew 11:7-15 and Matthew 17:10-13.

22 Then said they unto him, Who art thou? that we may give an answer to them that sent us. What sayest thou of thyself?

[That we may give an answer to them that sent us] These Pharisees were probably a deputation from the grand Sanhedrin; the members of which, hearing of the sucess of the Baptist's preaching, were puzzled to know what to make of him, and seriously desired to hear from himself what he professed to be.

23 He said, I am the voice of one crying in the wilderness, Make straight the way of the Lord, as said the prophet Esaias.

[The voice of one crying in the wilderness] Or, the voice of a crier in the wilderness. This is quoted from Isaiah 40:3, which clearly proves that John the Baptist was the person of whom the prophet spoke. The idea is taken from the practice of eastern monarchs, who, whenever they took a journey, sent harbingers before them to prepare all things for their passage.

24 And they which were sent were of the Pharisees.
25 And they asked him, and said unto him, Why baptizest thou then, if thou be not that Christ, nor Elias, neither that prophet?

[Why baptizest thou then] Baptism was a very common ceremony among the Jews, who never received a proselyte into the full enjoyment of a Jew's privileges until he was both baptized and circumcized. But such baptisms were never performed except by an ordinance of the Sanhedrin, or in the presence of three magistrates; besides, they never baptized Jews, nor even the children of proselytes, for they were considered as born under the covenant and had no need of the introductory rite of baptism.
Now, as John had, in this respect, altered the common custom, admitting to his baptism Jews in general, the Sanhedrin took it for granted that no man had authority to make such changes unless especially commissioned from on high; and that only the prophet, or Elijah or the Messiah himself could have authority to act as John did.

26 John answered them, saying, I baptize with water: but there standeth one among you, whom ye know not;
27 He it is, who coming after me is preferred before me, whose shoe's latchet I am not worthy to unloose.

[I baptize with water] I use the common form, though I direct the baptized to a different end - that they should repent of their sins and believe in the Messiah.

[There standeth one among you] That is, the person whose forerunner I am is now dwelling in the land of Judea, and will shortly make his appearance among you. Christ was not present when John spoke thus, as may be seen from verse 29.

28 These things were done in Bethabara beyond Jordan, where John was baptizing.
29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.

[Behold the Lamb of God] This was said in allusion to what was spoken in Isaiah 53:7. Jesus was the true Lamb or Sacrifice required and appointed by God, of which those offered daily in the tabernacle and temple, Exodus 29:38-39, and especially the paschal lamb, were only types and representatives. See Exodus 12:4-5, 1 Corinthians 5:7. The continual morning and evening sacrifice of a lamb, under the Jewish law, was intended to point out the continual efficacy of the blood of atonement; for even at the throne of God Jesus Christ is ever represented as a lamb newly slain, Revelation 5:6. But John, pointing to Christ, calls him emphatically, The Lamb of God: - all the lambs which had been hitherto offered had been furnished by men. This was provided by GOD, as the only sufficient and available sacrifice for the sin of the world. In three esential respects this lamb differed from those by which it was represented. 1. It was the Lamb of God; the most excellent, fully effective. 2. It made an atonement for sin; it carried away sin in reality, the others only representatively. 3. It carried away the sin of the world, whereas, the other was offered only on behalf of the Jewish people.

30 This is he of whom I said, After me cometh a man which is preferred before me: for he was before me.
31 And I knew him not: but that he should be made manifest to Israel, therefore am I come baptizing with water.

[I knew him not] John [the Baptist] did not know our Lord personally and perhaps had never seen him at the time he spoke the words in verse 15. Nor is it any wonder that the Baptist should have been unacquainted with Christ, as he had spent thirty years in the hill country of Hebron while our Lord remained in the privacy of the obscure city of Nazareth, in the extreem borders of Galilee.

[But that he should be made manifest to Israel] One design of my publicly baptizing was that he, coming to my baptism, should be shown to be what he is by an extraordinary sign from heaven.

32 And John bare record, saying, I saw the Spirit descending from heaven like a dove, and it abode upon him.
33 And I knew him not: but he that sent me to baptize with water, the same said unto me, Upon whom thou shalt see the Spirit descending, and remaining on him, the same is he which baptizeth with the Holy Ghost.
34 And I saw, and bare record that this is the Son of God.

[I saw the Spirit descending] The event was the baptism of Jesus as recorded in Matthew 3:13-17.

[He that sent me - said unto me] From this we may clearly perceive that John had a most intimate acquaintance with God.

[This is the Son of God.] Mission accomplished. Thank you John.