Galatians 4:28-31

And you brethren, like Isaac, are children of promise. But as at that time he who was born according to the flesh persecuted him who was born according to the Spirit, so it is now also. But what does the Scripture say? “CAST OUT THE BONDWOMAN AND HER SON, FOR THE SON OF THE BONDWOMAN SHALL NOT BE AN HEIR WITH THE SON OF THE FREE WOMAN.” So then, brethren, we are not children of a bondwoman, but of the free woman.