Scripture says that Abraham had two sons, one the child of the slave-woman and the other the child of the free woman.
But the child of the slave-woman was born in the course of nature, while the child of the free woman was born in fulfillment of a promise.
But what does the passage of Scripture say? 'Send away the slave-woman and her son; for the slave's son shall not be co-heir with the son of the free woman.'
And so, Brothers, we are not children of a slave, but of her who is free.