For it is written that Abraham had two sons, one by the slave woman and one by the free woman.
But the son of the slave woman was born according to the flesh, while the son of the free woman was born through the promise.
But what does the Scripture say? “Cast out the slave woman and her son, for the son of the slave woman shall not inherit with the son of the free woman.”
So, brothers, we are not children of the slave woman, but of the free woman.