26. But the Jerusalem that is above is free. She is our mother.
27. It is written, "Be glad, woman, you who have no children. Start shouting, you who have no labor pains. The woman who is all alone has more children than the woman who has a husband." (Isaiah 54:1)
28. Brothers and sisters, you are children because of God's promise just as Isaac was.
29. At that time, the son born in the usual way tried to hurt the son born by the power of the Holy Spirit. It is the same now.
30. But what does Scripture say? "Get rid of the slave woman. Get rid of her son. The slave woman's son will never have a share of the family's property with the free woman's son." (Genesis 21:10)