[28] Now brethren, Isaac was, the children of promise. [29] But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now. [30] Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman be heir with the son of the freewoman. [31] brethren, not children of the bondwoman, but of the free.