From: John 16:16-20
Fullness of Joy
(Jesus said to His disciples,)  "A little while, and you will see Me no more; again a little while, and you will see Me."  Some of His disciples said to one another, "What is this that He says to us, `A little while, and you will not see Me, and again a little while, and you will see Me'; and, `because I go to the Father'?"  They said, "What does He mean by `a little while'? We do not know what He means."  Jesus knew they wanted to ask Him; so He said to them, "Is this what you are asking yourselves, what I meant by saying, `A little while and you will not see Me, and again a little while, and you will see Me'?  Truly, truly, I say to you, you will weep and lament, but the world will rejoice; you will be sorrowful, but your sorrow will turn into joy."
16-20. Earlier our Lord consoled the disciples by assuring them that He would send them the Holy Spirit after He went away (verse 7). Now He gives them further consolation: He is not leaving them permanently, He will come back to stay with them. However, the Apostles fail to grasp what He means, and they ask each other what they make of it. Our Lord does not give them a direct explanation, perhaps because they would not understand what He meant (as happened before: cf. Matthew 16:21-23 and paragraph). But He does emphasize that though they are sad now they will soon be rejoicing: after suffering tribulation they will be filled with a joy they will never lose (cf. John 17:13). This is a reference primarily to the Resurrection (cf. Luke 24:41), but also to their definitive encounter with Christ in Heaven.
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.