For it is written that Abraham had two sons, one by a slave woman and the other by a free woman.
One, the child of the slave, was born according to the flesh; the other, the child of the free woman, was born through the promise.
Now this is an allegory: these women are two covenants. One woman, in fact, is Hagar, from Mount Sinai, bearing children for slavery.
Now Hagar is Mount Sinai in Arabia a and corresponds to the present Jerusalem, for she is in slavery with her children.
But the other woman corresponds to the Jerusalem above; she is free, and she is our mother.
For it is written, "Rejoice, you childless one, you who bear no children, burst into song and shout, you who endure no birth pangs; for the children of the desolate woman are more numerous than the children of the one who is married."
Now you, b my friends, c are children of the promise, like Isaac.
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved. (New Revised Standard Bible Version Online)