When ye have lifted up - When you have crucified. See John 3:14 note; also John 12:32 note.

The Son of man - See the notes at Matthew 8:19-20.

Then shall ye know - Then shall you have evidence or proof.

That I am he - Am the Messiah, which I have professed to be.

And that I do nothing of myself - That is, you shall have proof that God has sent me; that I am the Messiah; and that God concurs with me and approves my doctrine. This proof was furnished by the miracles that attended the death of Jesus - the earthquake and darkness; but chiefly by his resurrection from the dead, which proved, beyond a doubt, that he was what he affirmed he was - the Messiah.

When ye have lifted up - When ye have crucified me, and thus filled up the measure of your iniquities, ye shall know that I am the Christ, by the signs that shall follow; and ye shall know that what I spoke is true, by the judgments that shall follow. To be lifted up, is a common mode of expression, among the Jewish writers, for to die, or to be killed.

Then said Jesus unto them,.... Upbraiding them with their ignorance, and giving them a sign, as well as pointing out the time when they either, by good or sad experience, should have knowledge of him:

when ye have lift up the son of man; meaning himself, who was to be lifted up upon the cross, as the serpent was upon the pole, in the wilderness; and which signified the manner of death he should die, the death of the cross; and suggested, that what the Jews designed for his reproach, shame, and abasement, would be the way and means of his rise and exaltation; and this lifting him up, or crucifying him, he ascribes to them, because they would deliver him to Pontius Pilate to be condemned, and stir up the people to ask, and be importunate themselves for his crucifixion:

then shall ye know that I am he; the Son of God, and true Messiah, as the centurion, and those that were with him, did, when they observed the earthquake; and the things that were done at his death; and after the death, resurrection, and ascension of Christ, and the pouring forth of his Spirit, many of the Jews had not only a notional, but a true and spiritual knowledge of Jesus, as the Messiah; and upon the destruction of their temple, city, and nation, and their disappointment by false Christs, they doubtless many of them must, and did know, that the true Messiah was come, and that Jesus of Nazareth was he:

and that I do nothing of myself; See Gill on John 5:19;

but as my Father hath taught me, I speak these things; this he says not as lessening himself, or making himself inferior to the Father, but to show the excellency of his doctrine, and to assert the original, authority, and divinity of it; suggesting that it was not an human doctrine, or a device of man's, or his own, as man, but was divine, and from God; see John 7:16.

Lifted up

See on John 3:14.

Ye shall know (γνώσεσθε)

Render, perceive, here as in John 8:27.

I am He

As in John 8:24, on which see note.

Of myself (ἀπ' ἐμαυτοῦ)

Properly, from myself, as Rev., at John 7:17, but not here. See on John 7:17.

Hath taught (ἐδίδαξεν)

Rev., more correctly, taught. The aorist tense, regarding the teaching as a single act. Compare ἤκουσα, I heard, John 3:32.

I speak these things (παῦτα λαλῶ)

Not equivalent to so I speak (i.e., as the Father taught me), but an absolute declaration with reference to these present revelations.

Then said Jesus unto them, When ye have lifted up the Son of man, then shall ye know that I am he, and that I do nothing of myself; but as my Father hath taught me, I speak these things.

8:28 When ye have lifted up the Son of man. Lifted him up on the cross. His lifting up would be the means of breaking down unbelief. We can see how this was verified. In fifty days after he was lifted up three thousand believed in a single day (Ac 2:41), and the work of faith went on until the civilized world acknowledged him as King.

8:28 When ye shall have lifted up - On the cross, ye shall know - And so many of them did, that I AM - God over all; and that I do nothing of myself - Being one with the Father.

Margin Son of man

See Scofield Note: "Mt 8:20".

28-30. When ye have lifted up the Son of man-The plainest intimation He had yet given in public of the manner and the authors of His death.

then shall ye know that I am he, &c.-that is, find out, or have sufficient evidence, how true was all He said, though they would be far from owning it.

8:21-29 Those that live in unbelief, are for ever undone, if they die in unbelief. The Jews belonged to this present evil world, but Jesus was of a heavenly and Divine nature, so that his doctrine, kingdom, and blessings, would not suit their taste. But the curse of the law is done away to all that submit to the grace of the gospel. Nothing but the doctrine of Christ's grace will be an argument powerful enough, and none but the Spirit of Christ's grace will be an agent powerful enough, to turn us from sin to God; and that Spirit is given, and that doctrine is given, to work upon those only who believe in Christ. Some say, Who is this Jesus? They allow him to have been a Prophet, an excellent Teacher, and even more than a creature; but cannot acknowledge him as over all, God blessed for evermore. Will not this suffice? Jesus here answers the question. Is this to honour him as the Father? Does this admit his being the Light of the world, and the Life of men, one with the Father? All shall know by their conversion, or in their condemnation, that he always spake and did what pleased the Father, even when he claimed the highest honours to himself.