Galatians 4:21-31 - Hagar And Sarah Represent Two Covenants
21 Say, you whose desire it is to be under the law, do you not give ear to the law? 22 Because it is in the Writings, that Abraham had two sons, one by the servant-woman, and one by the free woman. 23 Now the son by the servant-woman has his birth after the flesh; but the son by the free woman has his birth through the undertaking of God. 24 Which things have a secret sense; because these women are the two agreements; one from the mountain of Sinai, giving birth to servants, which is Hagar. 25 Now this Hagar is the mountain Sinai in Arabia, and is the image of the Jerusalem which now is: which is a servant with her children. 26 But the Jerusalem on high is free, which is our mother. 27 For it is in the Writings, You who have never given birth, be glad; give cries of joy, you who have had no birth-pains; for the children of her who has been given up by her husband are more than those of the woman who has a husband.
28 Now we, brothers, as Isaac was, are the children of the undertaking of God. 29 But as in those days he who had birth after the flesh was cruel to him who had birth after the Spirit, even so it is now. 30 What then do the Writings say? Send away the servant-woman and her son; for the son of the servant-woman will not have a part in the heritage with the son of the free woman.
31 So, brothers, we are not children of the servant-woman, but of the free woman.