First in a series of studies in Isaiah 54
“ ‘Sing, O barren.
You who have not borne!
Break forth into singing,
And cry aloud,
You who have not travailed with child!
For more are the children of the desolate
Than the children of the married woman,’ says the Lord” (Isaiah 54.1).
When Israel returns from the bondage of Babylon, she finds that her numbers have significantly decreased, leaving her with fewer than the number who had returned from Egyptian bondage so many years before.
On the primary level of the prophecy, the “desolate” are Gentiles who do not have a relationship with God—they have been blessed and their numbers have increased. The “married woman” stands for the Israelites who experienced a devastating decrease in number during the captivity.
But Isaiah here tells the Israelites they have reason to rejoice. He says they should break forth into song and express their gratitude to God because they are looking to a better future.
The secondary meaning of the prophecy is about the church and the Christian Age. The "desolate" are those who do not have a scriptural relationship with God, but sometimes it appears they are abundantly blessed. The "married woman" represents those who have come to Christ but are not always blessed so much in this life: their real blessing will be in the age to come.