But the Jerusalem above is free, and she is our mother.
For it is written: Rejoice, O barren woman who does not give birth. Break forth and shout, you who are not in labor, for the children of the desolate are many, more numerous than those of the woman who has a husband.
Now you, brothers, like Isaac, are children of promise.
But just as then the child born according to the flesh persecuted the one born according to the Spirit, so also now.
But what does the Scripture say? Throw out the slave and her son, for the son of the slave will never inherit with the son of the free woman.