SUBJECT:  “That Prophet” –John 1:21

QUESTION:  Who is being referred to here?

ANSWER:

First, the verse in question:

John 1:21-25

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

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?

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.

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?

Now the commentaries:

John 1:21

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. See Matthew 17:10; and this belief of theirs they supported by a literal construction of Malachi 4:5.

[Art thou that prophet?] The prophet spoken of by Moses, Deuteronomy 18:15, 18. This text they had also misunderstood: for the prophet or teacher promised by Moses was no other than the Messiah himself. See Acts 3:22. But the Jews had a tradition that Jeremiah was to return to life, and restore the pot of manna, the ark of the covenant, etc., which he had hidden that the Babylonians might not get them. Besides this, they had a general expectation that all the prophets should come to life in the days of the Messiah.

[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 11:14; 17:10-13.  ~from Adam Clarke's Commentary

Matthew 11:14 

And if ye will receive it, this is Elias, which was for to come.

Matthew 17:10-13

10 And his disciples asked him, saying, Why then say the scribes that Elias must first come?

11 And Jesus answered and said unto them, Elias truly shall first come, and restore all things.

12 But I say unto you, That Elias is come already, and they knew him not, but have done unto him whatsoever they listed. Likewise shall also the Son of man suffer of them.

13 Then the disciples understood that he spake unto them of John the Baptist.

Another commentary:

John 1:19-21

By that prophet we are probably to understand the prophet of Deuteronomy 18:15, 18. By some he was taken to be distinct from the Messiah (John 7:40). ~from The Wycliffe Bible Commentary

Let us take a look at the referred to Deuteronomy 18:15, 18:

Deuteronomy 18:15

The LORD thy God will raise up unto thee a Prophet from the midst of thee, of thy brethren, like unto me; unto him ye shall hearken;

Deuteronomy 18:18

I will raise them up a Prophet from among their brethren, like unto thee, and will put my words in his mouth; and he shall speak unto them all that I shall command him.

Note:  Clearly speaking of Jesus.  Notice Acts 3:22 which is also referred to in the commentary above:

Acts 3:22

For Moses truly said unto the fathers, A prophet shall the Lord your God raise up unto you of your brethren, like unto me; him shall ye hear in all things whatsoever he shall say unto you.

Here is the commentary on Acts 3:22

Acts 3:22-25

For Moses truly said unto the fathers, A prophet shall the Lord your God raise up unto you of your brethren, like unto me; him shall ye hear in all things whatsoever he shall say unto you.

These days of which Peter speaks were foretold as far back as Moses, who prophesied that God would raise up another prophet like himself (Deuteronomy 18:15-19), who would bring the word of God to his people with authority. The threat contained in verse 23 is combined from Deuteronomy 18:19 and Leviticus 23:29. 24, 25. These days of redemption that Peter was proclaiming were the constant theme of the prophets from the time of Samuel. The Jews were the sons of the prophets and of the covenant made with Abraham and were therefore the natural heirs of these Messianic promises. ~from The Wycliffe Bible Commentary

So, we see that the “prophet” spoken of was Jesus Christ.