Galatians 4:22-28

22For it is written that Abraham had two sons, one by the slave woman [Hagar] and one by the free woman [Sarah].

23But the child of the slave woman was born according to the flesh and had an ordinary birth, while the son of the free woman was born in fulfillment of the promise.

24Now these facts are about to be used [by me] as an allegory [that is, I will illustrate by using them]: for these women can represent two covenants: one [covenant originated] from Mount Sinai [where the Law was given] that bears children [destined] for slavery; she is Hagar.

25Now Hagar is (represents) Mount Sinai in Arabia and she corresponds to the present Jerusalem, for she is in slavery with her children.

26But the Jerusalem above [that is, the way of faith, represented by Sarah] is free; she is our mother.

27For it is written [in the Scriptures], “Rejoice, o barren woman who has not given birth; Break forth into a [joyful] shout, you who are not in labor; For the desolate woman has many more children Than she who has a husband.”

28And we, [believing] brothers and sisters, like Isaac, are children [not merely of physical descent, like Ishmael, but are children born] of promise [born miraculously].