Yahweh telling the people of Jerusalem to rejoice because there will be many people living in Jerusalem again is spoken of as if Yahweh were telling a barren women she is going to have many children. (See: [[rc://en/ta/man/translate/figs-metaphor]])
# break into joyful singing and cry aloud, you who have never been in birth labor
This statement means the same thing as the first part of the sentence. (See: [[rc://en/ta/man/translate/figs-parallelism]])
# For the children of the desolate one are more
An event that will happen in the future is spoken of as if it happened in the past. This emphasizes that the event will certainly happen. AT: "For the children of the desolate woman will be more" (See: [[rc://en/ta/man/translate/figs-pastforfuture]])