This is he, of whom it is said,.... Either the day before, as in John 1:27, or some time before that, John 1:15, when he first began to baptize, even before Christ came to be baptized by him, and before he personally knew him; see Matthew 3:11.

After me cometh a man; not a mere man, but the man God's fellow: and this is said, not because he was now a grown man, or to show the truth of his human nature; but seems to be a common Hebraism, and is all one as if it had been said, "after me cometh one", or a certain person: for the sense of this phrase, and what follows; see Gill on John 1:15.

Of whom (περὶ οὗ)

i.e., "concerning whom;" but the proper reading is ὑπὲρ οὗ, "on behalf of whom;" in vindication of.

A man (ἀνὴρ)

Three words are used in the New Testament for man: ἄῤῥην, or ἄρσην, ἀνήρ, and ἄνθρωπος. Ἄρσην marks merely the sexual distinction, male (Romans 1:27; Revelation 12:5, Revelation 12:13). Ἁνήρ denotes the man as distinguished from the woman, as male or as a husband (Acts 8:12; Matthew 1:16), or from a boy (Matthew 14:21). Also man as endowed with courage, intelligence, strength, and other noble attributes (1 Corinthians 13:11; Ephesians 4:13; James 3:2).

Ἄνθρωπος is generic, without distinction of sex, a human being (John 16:21), though often used in connections which indicate or imply sex, as Matthew 19:10; Matthew 10:35. Used of mankind (Matthew 4:4), or of the people (Matthew 5:13, Matthew 5:16; Matthew 6:5, Matthew 6:18; John 6:10). Of man as distinguished from animals or plants (Matthew 4:19; 2 Peter 2:16), and from God, Christ as divine and angels (Matthew 10:32; John 10:33; Luke 2:15). With the notion of weakness leading to sin, and with a contemptuous sense (1 Corinthians 2:5; 1 Peter 4:2; John 5:12; Romans 9:20). The more honorable and noble sense thus attaches to ἀνήρ rather than to ἄνθρωπος. Thus Herodotus says that when the Medes charged the Greeks, they fell in vast numbers, so that it was manifest to Xerxes that he had many men combatants (ἄνθρωποι) but few warriors (ἄνθρωποι) vii., 210. So Homer: "O friends, be men (ἀνέρες), and take on a stout heart" ("Iliad," v., 529). Ἁνήρ is therefore used here of Jesus by the Baptist with a sense of dignity. Compare ἄνθρωπος, in John 1:6, where the word implies no disparagement, but is simply indefinite. In John ἀνήρ has mostly the sense of husband (John 4:16-18). See John 6:10.

This is he of whom I said, After me cometh a man which is preferred before me: for he was before me.

1:30 This is he of whom I said. See Joh 1:27.

He was before me. Existed before I was born.

1:29-36 John saw Jesus coming to him, and pointed him out as the Lamb of God. The paschal lamb, in the shedding and sprinkling of its blood, the roasting and eating of its flesh, and all the other circumstances of the ordinance, represented the salvation of sinners by faith in Christ. And the lambs sacrificed every morning and evening, can only refer to Christ slain as a sacrifice to redeem us to God by his blood. John came as a preacher of repentance, yet he told his followers that they were to look for the pardon of their sins to Jesus only, and to his death. It agrees with God's glory to pardon all who depend on the atoning sacrifice of Christ. He takes away the sin of the world; purchases pardon for all that repent and believe the gospel. This encourages our faith; if Christ takes away the sin of the world, then why not my sin? He bore sin for us, and so bears it from us. God could have taken away sin, by taking away the sinner, as he took away the sin of the old world; but here is a way of doing away sin, yet sparing the sinner, by making his Son sin, that is, a sin-offering, for us. See Jesus taking away sin, and let that cause hatred of sin, and resolutions against it. Let us not hold that fast, which the Lamb of God came to take away. To confirm his testimony concerning Christ, John declares the appearance at his baptism, in which God himself bore witness to him. He saw and bare record that he is the Son of God. This is the end and object of John's testimony, that Jesus was the promised Messiah. John took every opportunity that offered to lead people to Christ.