John 1:29-31

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.

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.

John knew of the prophecies of Jesus as Lamb. He was oppressed, and He was afflicted, yet He opened not his mouth: He is brought as a lamb to the slaughter, and as a sheep before her shearers is dumb, so He openeth not his mouth (Isaiah 53:7).

taketh away = take up, bear

taketh away sin (singular) — Christ’s cross-work, but also the ultimate removal of sin and its consequences in the new Heaven and new Earth. And He said unto me, It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely (Revelation 21:6).

This is He — John reminds his listeners of what he said the day before.

In the other gospels, John the Baptist announced Jesus as a lion — but that’s His second (kingdom) coming. This time, He came as a lamb.

I did not know Him — Probably John hadn’t seen Jesus before this, but even if he had, he didn’t know Him as Messiah until he saw the Spirit like a dove.

John came and baptized to make Israel aware of Christ’s coming, to prepare them.

Lamb:

• sinless — But with the precious blood of Christ, as of a lamb without blemish and without spot (1 Peter 1:19)

• willing (led) — He was led as a sheep to the slaughter; and like a lamb dumb before his shearer, so opened He not His mouth (Acts 8:32).

• sacrifice — For then must He often have suffered since the foundation of the world: but now once in the end of the world hath He appeared to put away sin by the sacrifice of Himself (Hebrews 9:26).