For it is written: Abraham had two sons, the one out of the slave-woman, and one out of the free woman.
And Hagar bore Abram a son. And Abram called his son's name, which Hagar bore, Ishmael.
And she said to Abraham, Cast out this slave woman and her son. For the son of this slave woman shall not be heir with my son, with Isaac.
But, indeed, he out of the slave-woman has been born according to flesh, and he out of the free woman through the promise;
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."
Then, brothers, we are not children of a slave-woman, but of the free woman.