ISB ~ Galatians 4 v24 - 31

The mothers of Isaac and Ishmael represent two distinct covenants and thus two ages of salvation history. The slave woman, Hagar, is linked with Mount Sinai, where the Torah was given to Israel; the essence of this covenant was practiced and promoted in Jerusalem. The free woman, Sarah, is symbolic of the heavenly Jerusalem above, where the saints worship God in the freedom of the New Covenant (Heb 12:2223) without the burdensome yoke of the Mosaic Law (Gal 5:1). A contrast is thus set up between the Judaizers and the Galatians:the former are sons of the earthly Jerusalem, who are born into religious slavery through the Law (like Ishmael, from Hagar), while the latter are sons of the heavenly Jerusalem (CCC 757), who are born into freedom and blessedness through the gospel (like Isaac, from Sarah). See note on Gal 3:15-18.