You will weep and lament. He shows for what reason he foretold that his departure was at hand, and, at the same time, added a promise about his speedy return. It was, that they might understand better that the aid of the Spirit was highly necessary. "A hard and severe temptation," says he, "awaits you; for, when I shall be removed from you by death, the world will proclaim its triumphs over you. You will feel the deepest anguish. The world will pronounce itself to be happy, and you to be miserable. I have resolved, therefore, to furnish you with the necessary arms for this warfare." He describes the interval that elapsed between his death and the day when the Holy Spirit was sent; [1] for at that time their faith, so to speak, lay prostrate and exhausted. Your sorrow will be turned into joy. He means the joy which they felt after having received the Spirit; not that they were afterwards free from all sorrow, but that all the sorrow which they would endure was, swallowed up by spiritual joy We know that the apostles: so long as they lived, sustained a severe warfare, that they endured base reproaches, that they had many reasons for weeping and lamenting; but, renewed by the Spirit, they had laid aside their former consciousness of weakness, so that, with lofty heroism, they nobly trampled under foot all the evils that they endured. Here then is a comparison between their present weakness and the power of the Spirit, which would soon be given to them; for, though they were nearly overwhelmed for a time, yet afterwards they not only fought bravely, but obtained a glorious triumph in the midst of their struggles. Yet it ought also to be observed, that he points out not only the interval that elapsed between the resurrection of Christ and the death of the apostles, but also the period which followed afterwards; as if Christ had said, "You will lie prostrate, as it were, for a short time; but when the Holy Spirit shall have raised you up again, then will begin a new joy, which will continue to increase, until, having been received into the heavenly glory, you shall have perfect joy."

Footnotes

1 - "Et le jour que le S. Esprit fut envoye."

Ye shall weep - At my crucifixion, sufferings, and death. Compare Luke 23:27.
The world - Wicked men. The term world is frequently used in this sense. See John 16:8. It refers particularly, here, to the Jews who sought his death, and who would rejoice that their object was obtained.
Shall be turned into joy - You will not only rejoice at my resurrection, but even my death, now the object of so much grief to you, will be to you a source of unspeakable joy. It will procure for you peace and pardon in this life, and eternal joy in the world to come. Thus their greatest apparent calamity would be to them, finally, the source of their highest comfort; and though then they could not see how it could be, yet if they had known the whole case they would have seen that they might rejoice. As it was, they were to be consoled by the assurance of the Saviour that it would be for their good. And thus, in our afflictions, if we could see the whole case, we should rejoice. As it is, when they appear dark and mysterious, we may trust in the promise of God that they will be for our welfare. We may also remark here that the apparent triumphs of the wicked, though they may produce grief at present in the minds of Christians, will be yet overruled for good. Their joy shall be turned into mourning, and the mourning of Christians into joy; and wicked men may be doing the very thing - as they were in the crucifixion of the Lord Jesus - that shall yet be made the means of promoting the glory of God and the good of his people, Psalm 76:10.

Ye shall weep and lament - To see me crucified and laid in the grave.
But the world shall rejoice - The chief priests, scribes, Pharisees, and persecuting Jews in general, will triumph, hoping that their bad cause is crowned with success.
But your sorrow shall be turned into joy - When ye see me risen from the dead.
It is very evident that our Lord uses the word world, in several parts of this discourse of his, to signify the unbelieving and rebellious Jews.

Verily, verily, I say unto you,.... A strong asseveration, a way of speaking often used by him, when he solemnly affirms any thing, and would assure of the truth of it, as here:
that ye shall weep and lament; meaning at his death, when he should be removed from them, so that they should not see him; when they should be filled with inward grief on account thereof, and express it by mournful gestures, and a doleful voice; and which was fulfilled in them, Mark 16:10; and how pensive the two disciples were that were going to Emmaus, it is easy to observe from the account given of them;
but the world shall rejoice; the unbelieving Jews; and not only the common people, but the chief priests, with the Scribes and elders, mocked at him, insulted him, and triumphed over him when on the cross, being glad at heart they had got him there; imagining now, that it was all over, the day was their own, and they should be no more disturbed by Christ and his followers:
and ye shall be sorrowful; Christ repeats it again, and uses a variety of words to express the greatness of their sorrow, and the many ways in which they would signify it:
but your sorrow shall be turned into joy; as it was, when he was raised from the dead, which was so wonderful and surprising to them, that for joy they could scarce believe their own eyes; it being a mercy unexpected, though they had been told of it, and too great for them to enjoy; yea, that very thing which was the occasion of their sorrow, became the foundation of their joy; namely, the death of Christ, salvation, and all the benefits and blessings of grace coming to them in this way.

Ye shall weep and lament, but the world shall rejoice. How sad were the broken-hearted disciples, as they wept at the tomb! At the same time their enemies were gloating over their triumph. Soon all was changed, for your sorrow shall be turned into joy. The glad news came, "The Lord is risen!" Then they heard that "all power was his," saw him ascend into heaven, and "returned to Jerusalem with great joy."

Ye will weep and lament - When ye see me dead; but your sorrow will be turned into joy - When ye see me risen.