21Tell me, you who desire to be under the law, do you not listen to the law?22For it is written that Abraham had two sons, one by a slave woman and one by a free woman.23But the son of the slave was born according to the flesh, while the son of the free woman was born through promise.24Now this may be interpreted allegorically: these women are two covenants. One is from Mount Sinai, bearing children for slavery; she is Hagar.25Now Hagar is Mount Sinai in Arabia; she corresponds to the present Jerusalem, for she is in slavery with her children.26But the Jerusalem above is free, and she is our mother.27For it is written, "Rejoice, O barren one who does not bear; break forth and cry aloud, you who are not in labor! For the children of the desolate one will be more than those of the one who has a husband."28Now you, brothers, like Isaac, are children of promise.29But just as at that time he who was born according to the flesh persecuted him who was born according to the Spirit, so also it is now.30But what does the Scripture say? "Cast out the slave woman and her son, for the son of the slave woman shall not inherit with the son of the free woman."31So, brothers, we are not children of the slave but of the free woman.