Charles Ellicott Commentary John 16:20

"Verily, verily, I say unto you, that ye shall weep and lament, but the world shall rejoice: ye shall be sorrowful, but your sorrow shall be turned into joy." — John 16:20 (ASV)

Verily, verily, I say unto you.—Compare Note on John 1:51.

That ye shall weep and lament, but the world shall rejoice.—Compare John 20:11 and Luke 23:27. In the original, the contrast between the sorrow of the disciples and the joy of the world is made more striking by the order of the words, “Weep and lament shall ye, but the world shall rejoice.” The tears and the scoffs at the cross were the fulfillment of this prophecy.

And ye shall be sorrowful, but your sorrow shall be turned into joy.

The expression is a full one. It is not simply that they will pass from sorrow to joy, but that the sorrow itself will become joy.

They will rejoice in the presence of the Lord when, after a little while, they will see Him and will feel that the separation necessarily preceded the union, and that the sorrow was itself a matter of joy because it was the necessary cause of the joy (John 16:7 and John 20:20).