Sarah's demand about Ishmael in Genesis 21:10 becomes a guideline (see Genesis 21:12) for dealing with the current son of the slave woman (anyone who refuses to abandon slavery to the law). God does not let those who try to be righteous through their own efforts share in his inheritance (see Romans 9:30–33). Those who come to God through Jesus Christ alone, by faith and not by following the law, are children of the free woman who inherit God's blessings.