MKJV(i)
28 But brothers, we, like Isaac, are children of promise.
29 But then even as he born according to flesh persecuted him born according to the Spirit, so it is also now.
30 But what does the Scripture say? "Cast out the slave-woman and her son; for in no way shall the son of the slave-woman inherit with the son of the free woman."
31 Then, brothers, we are not children of a slave-woman, but of the free woman.