For it is written: "Rejoice, O barren woman who does not bear children; break forth and shout, you who have no birth pains, because the children of the desolate woman are more numerous than those of the woman who has a husband."

But what does the scripture say? "Throw out the slave woman and her son, for the son of the slave woman will not share the inheritance with the son" of the free woman.

For it is written that Abraham had two sons, one by the slave woman and the other by the free woman.

But one, the son by the slave woman, was born by natural descent, while the other, the son by the free woman, was born through the promise.

Therefore, brothers and sisters, we are not children of the slave woman but of the free woman.