From: John 16:20-23
Fullness of Joy (Continuation)
(Jesus said to His disciples,)  "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.  When a woman is in travail she has sorrow, because her hour has come; but when she is delivered of the child, she no longer remembers the anguish, for joy that a child is born into the world.  So you have sorrow now, but I will see you again and your hearts will rejoice, and no one will take your joy from you.  In that day you will ask nothing of Me. Truly, truly, I say to you, if you ask anything of the Father, He will give it to you in My name."
21-22. This image of the woman giving birth (frequently used in the Old Testament to express intense pain) is also often used, particularly by the prophets, to mean the birth of the new messianic people (cf. Isaiah 21:3; 26:17; 66:7; Jeremiah 30:6; Hosea 13:13; Micah 4:9-10). The words of Jesus reported here seem to be the fulfillment of those prophecies. The birth of the messianic people--the Church of Christ--involves intense pain, not only for Jesus but also, to some degree, for the Apostles. But this pain, like birthpains, will be made up for by the joy of the final coming of the Kingdom of Christ: "I am convinced," says St. Paul, "that the sufferings of this present time are not worth comparing with the glory that is to be revealed to us" (Romans 8:18).
23-24. See the note on John 14:12-14.
[Note on John 14:12-14 states:
12-14. Jesus Christ is our intercessor in Heaven; therefore, He promises us that everything we ask for in His name, He will do. Asking in His name (cf. 15:7, 16; 16:23-24) means appealing to the power of the risen Christ, believing that He is all-powerful and merciful because He is true God; and it also means asking for what is conducive to our salvation, for Jesus is our Savior. Thus, by "whatever you ask" we must understand what is for the good of the asker. When our Lord does not give what we ask for, the reason is that it would not make for our salvation. In this way we can see that He is our Savior both when He refuses us what we ask and when He grants it.]
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.