Galatians 4:21-31 - Hagar And Sarah Represent Two Covenants
21 Tell me, those desiring to be under Law, do you not hear the Law? 22 For it is written: Abraham had two sons, the one out of the slave-woman, and one out of the free woman. 23 But, indeed, he out of the slave-woman has been born according to flesh, and he out of the free woman through the promise; 24 which things are being allegorized; for these are the two covenants, one indeed from Mount Sinai bringing forth to slavery, which is Hagar. 25 For Hagar is Mount Sinai in Arabia, and answers to Jerusalem which now is, and is in slavery with her children. 26 But the Jerusalem from above is free, who is the mother of us all. 27 For it is written, "Rejoice, barren one not bearing; break forth and shout, you not travailing; for more are the children of the desolate than she having the husband."
28 But brothers, we, like Isaac, are children of promise. 29 But then even as he born according to flesh persecuted him born according to the Spirit, so it is also now. 30 But what does the Scripture say? "Cast out the slave-woman and her son; for in no way shall the son of the slave-woman inherit with the son of the free woman."
31 Then, brothers, we are not children of a slave-woman, but of the free woman.