Sarah and Hagar
“For this Hagar is Mount Sinai in Arabia, and corresponds to Jerusalem which now is, and is in bondage with her children—but the Jerusalem above is free, which is the mother of us all. For it is written: ‘Rejoice, O barren, you who do not bear! Break forth and shout, you who do not travail! For the desolate has many more children than she who has a husband.’ Now we, brethren, as Isaac was, are children of promise.” Gal. 4:22-28.
The one who has the most children has reason to rejoice most, and in this case it is Sarah. Hagar is a type of the law. Hagar began to bear children from the time the law was given on Sinai until Christ. She bore many children during all those years, but the law applied only to the Jews. Abraham’s seed descended through Isaac, which is Christ. Gal. 3:16. Sarah did not begin to bear children before Christ came, and she will continue to bear from that time on until Christ’s return. That will be for a longer time than when the law applied; and besides, Sarah does not just bear among Jews, but also among all nations. “In you all the nations of the earth will be blessed.” Thus Sarah will have many more children than Hagar.
“Enlarge the place of your tent, and let them stretch out the curtains of your habitations; do not spare; lengthen your cords, and strengthen your stakes. For you shall expand to the right and to the left, and your descendants will inherit the nations, and make the desolate cities inhabited.” Isa. 54:2-3.
Ishmael was born according to the flesh. The man went into Hagar. “Yet the law is not of faith, but ‘The man who does them shall live by them.’” Gal. 3:12. The law had to be kept in man’s own strength, which is why they were born to bondage. On the other hand, Isaac was born by faith, and in Christ Jesus the only thing that avails anything is faith working through love. Gal. 5:6. Thus they are born to liberty.