27 For it is written, “Rejoice, O barren woman, who does not give birth to children; burst out and shout, you who do not have birth pains, because many are the children of the desolate woman, even more than those of the one who has a husband.”
28 But you, brothers, are children of the promise, just as Isaac.
29 But just as at that time the child born according to human descent persecuted the child born according to the Spirit, so also now.
30 But what does the scripture say? “Drive out the female slave and her son, for the son of the female slave will never inherit with the son” of the free woman.
31 Therefore, brothers, we are not children of the female slave but of the free woman.