Tell me, you who want to be under the law, don’t you hear the law? For it is written that Abraham had two sons, one by a slave and the other by a free woman. But the one by the slave was born as a result of the flesh, while the one by the free woman was born through promise. These things are being taken figuratively, for the women represent two covenants. One is from Mount Sinai and bears children into slavery — this is Hagar. Now Hagar represents Mount Sinai in Arabia and corresponds to the present Jerusalem, for she is in slavery with her children. But the Jerusalem above is free, and she is our mother. For it is written,
Rejoice, childless woman,
unable to give birth.
Burst into song and shout,
you who are not in labor,
for the children of the desolate woman will be many,
more numerous than those
of the woman who has a husband.
Now you too, brothers and sisters, like Isaac, are children of promise. But just as then the child born as a result of the flesh persecuted the one born as a result of the Spirit, so also now. But what does the Scripture say? “Drive out the slave and her son, for the son of the slave will never be a coheir with the son of the free woman.” Therefore, brothers and sisters, we are not children of a slave but of the free woman.