3 And then He goes on to say, “A woman when she is in travail has sorrow, because her hour has come: but as soon as she is delivered of the child, she remembers no more the anguish, for joy that a man is born into the world. And ye now therefore have sorrow; but I will see you again, and your heart shall rejoice, and your joy no man takes from you.” Nor does the metaphor here employed seem difficult to understand; for its key is at hand in the exposition given by Himself of its meaning. For the pangs of parturition are compared to sorrow, and the birth itself to joy; which is usually all the greater when it is not a girl but a boy that is born. But when He said, “Your joy no man takes from you,” for their joy was Jesus Himself, there is implied what was said by the apostle, “Christ, being raised from the dead, dies no more; and death shall have no more dominion over Him.”
Source: Tractates on the Gospel of John (New Advent)