And I have told you now. It was proper that the disciples should be frequently admonished on this point; for it was a secret far exceeding all human capacity. He testifies that he foretells what shall happen, that, when it has happened, they may believe; for it was a useful confirmation of their faith when they brought to recollection the predictions of Christ, and saw accomplished before their eyes what they had formerly heard from his mouth. Yet it appears to be a sort of concession, as if Christ had said, "Because you are not yet capable of comprehending so deep a mystery, I bear with you till the event has happened, which will serve as an interpreter to explain this doctrine." Although for a time he seemed to speak to the deaf, yet it afterwards appeared that his words were not scattered in vain, or, as we may say, in the air, but that it was a seed thrown into the earth. Now, as Christ speaks here about his word and the accomplishment of events, so his death, and resurrection, and ascension to heaven, are combined with doctrine, that they may produce faith in us.

Before it come to pass - Before my death, resurrection, and ascension.
Ye might believe - You might be confirmed or strengthened in faith by the evidence which I gave that I came from God - the power of foretelling future events.

I have told you before it come to pass - Lest my death should be a stumbling-block to you, I have spoken of it beforehand, and showed you the necessity of it, that when it happens ye may believe, that as I could predict it so clearly, and so circumstantially, so all the good which I have promised shall be the result may be confidently expected by you; and that your sorrow, if not entirely removed, may at least be much mitigated.

And now I have told you before it came to pass,.... This is a strong proof of his true and proper deity, for none but the omniscient God can tell of things before they come to pass; this is peculiar to him, and distinguishes him from the gods of the Gentiles; see Isaiah 41:22;
that when it is come to pass, ye might believe: that is, that when he was removed from them, and gone to his Father, they might then believe that he was truly God, the Son of God, the promised Messiah; and that he was then in glory, and at the right hand of God.

I have told you - Of my going and return.