ACC ~ Galatians 4 v27a

SARAH DESERTED BECAUSE OF HER STERILITY. AUGUSTINE: Sarah signifies the heavenly Jerusalem, having been deserted for a long time by her husband’s embraces because of her perceived sterility. For men such as Abraham did not use women to satisfy lust but for the procreation of offspring. Now to her sterility age had also been added. … The age of Isaac’s parents serves to signify that, new though the people of the New Covenant are, their predestination lies nonetheless with God and is that heavenly Jerusalem of old. EPISTLE TO THE GALATIANS 40 [1B.4.21-31].

Gal