John 16:21

Jesus compared how the disciples would feel to the feelings of a pregnant woman at her delivery. This was an Old Testament illustration of how God’s people would feel when Messiah appeared (cf. Isaiah 21:3-5; Isaiah 26:16-21; Isaiah 66:7-14; Jeremiah 13:21; Micah 4:9-10). Jesus again used the word "hour" (Gr. hora, John 2:4; et al.) to focus the critical time of both painful experiences: His death and the woman’s delivery. What issues from the painful experience is so wonderful, in both cases, that the resulting joy replaces the former sorrow.