Sing, O barren one who did not bear;
burst into song and shout,
you who have not been in labour!
For the children of the desolate woman will be more
than the children of her that is married, says the Lord.
This is Second Isaiah, urging the Israeli people to move from their exile in Babylon now that Cyrus has freed them, and to return to their true homeland. The "barren one" in this verse is the city of Jerusalem, barren since her people have been taken. The promise is that her future will be greater than her past once her children have returned and have children of their own.
Metaphysically, each of us is Jerusalem, not merely "in favor with God" but truly the essence of God in expression. We are barren when we are "captive" in our human experience, unaware of our spiritual Power. Our human lives will be richer once we embrace that Power.
So it's up to us to decide to be either barren or fertile, and our lives will unfold accordingly.