Galatians 4:21-31 - Hagar And Sarah Represent Two Covenants
21 Tell me, ye that desire to be under the Law, do ye not hear the Law? 22 For it is written, that Abraham had two sons; the one by the bondwoman, the other by the freewoman. 23 But the one by the bondwoman was born after the flesh; while the one by the freewoman was through the promise. 24 Which things are written allegorically; for these women are two covenants; the one from Mount Sinai, who beareth children into bondage, which is Hagar; 25 for the word Hagar is Mount Sinai in Arabia; and she corresponds to the Jerusalem now existing, for she is in bondage with her children; 26 but the Jerusalem that is above is free, and she is our mother. 27 For it is written: "Rejoice, thou barren that bearest not; break forth and cry, thou that travailest not; for many are the children of the desolate one, rather than of her who hath the husband."
28 But ye, brethren, as Isaac was, are children of a promise. 29 But as at that time he that was born after the flesh persecuted him that was born through the Spirit, so it is now. 30 But what saith the scripture? "Cast out the bondwoman and her son; for the son of the bondwoman shall not be heir with the son of the freewoman."
31 So then, brethren, we are not children of a bondwoman, but of the freewoman.