21 Tell me, you who desire to be under the law, do you not hear the law?
22 For it is written that Abraham had two sons: the one by a bondwoman, the other by a freewoman.
23 But he who was of the bondwoman was born according to the flesh, and he of the freewoman through promise,
24 which things are symbolic. For these are the two covenants: the one from Mount Sinai which gives birth to bondage, which is Hagar —
25 for this Hagar is Mount Sinai in Arabia, and corresponds to Jerusalem which now is, and is in bondage with her children —
26 but the Jerusalem above is free, which is the mother of us all.
27 For it is written: “Rejoice, O barren, you who do not bear! Break forth and shout, you who are not in labor! For the desolate has many more children than she who has a husband.”
28 Now we, brethren, as Isaac was, are children of promise.
29 But, as he who was born according to the flesh then persecuted him who was born according to the Spirit, even so it is now.
30 Nevertheless what does the Scripture say? “Cast out the bondwoman and her son, for the son of the bondwoman shall not be heir with the son of the freewoman.”
31 So then, brethren, we are not children of the bondwoman but of the free.
hear the law (v.21) — the Old Testament. The Galatians were listening to the Judaizers who were pushing the Old Testament requirements. Paul asks them if they’ve stopped to listen to what the law really says.
Abraham’s two sons (v.22) were Ishmael, by Hagar, and Issac, by Sarah.
bondwoman (v.22) — Hagar, an Egyptian servant (slave) to Sarah.
freewoman (v.22) — Sarah, Abraham’s wife (and half-sister)
Not only do the two sons have different mothers, but they were born of different circumstances. Ismael resulted from the plan of Abraham and Sarah, relying on their own wisdom (Genesis 16:1-2). Isaac, the son promised by God, came by faith in God.
symbolic (v.24) — allegory. A true account of history, but also containing spiritual principles. Paul doesn’t reach this conclusion on his own, but is guided by the Spirit to do so (Galatians 1:11-112).
these (v.24) — Hagar and Sarah
covenants (v.24) — obligation taken on by God.
from Mount Sinai (v.24) — received on Mount Sinai
Hagar was a slave, and so her son was too — and so are those under the law. Hagar/Mount Sinai = where the law was given.
which is Hagar (v.24) — which is represented by Hagar in this allegory
corresponds to Jerusalem (v.25) —The earthly Jerusalem was in literal bondage (to Rome) and spiritual bondage with her children, the Jews.
Paul is comparing the law, represented by Sinai with the promise represented by the heavenly Jerusalem (v.26).
free (v.26) — not subject to the law
Jerusalem … which is the mother (v.26) — The city is where God chose to reign with His people, and where He someday will reign. It is where man’s redemption occurred. It would have been God’s dwelling place if Israel had accepted the offered kingdom. It is the representation of promise by faith. Sarah is the mother of those who are children by faith (v.31).
The quote in verse 27 is from Isaiah 54:1. Sarah was barren, so Abraham turned to Hagar, but later this was reversed and Hagar was exiled and Sarah returned to her rightful place.
we (v.28) — Gentiles, children by faith and not by flesh (not Jews)
As Ismael mocked Isaac, so all who seek salvation by faith will be mocked by those who seek it by law (v.29).
The quote in verse 30 is from Genesis 21:10. Sarah would not allow Ismael to inherit with Isaac and cast Hagar and Ismael out. So, those who follow the law won’t inherit spiritually with those who believe by faith alone.
we (v.31) — Paul and the Galatians are children of faith and free to inherit.
the handmaid (v.31) — should be a handmaid — there are many ways of spiritual slavery. The free woman — there is only one true way
Paul has appealed to the pride and to the affection of his readers; he now appeals to their intelligence. He addresses in particular those who were inclined to yield to the Judaizing party. They claim to understand the Mosaic law and are willing to be bound by its precepts. Surely, then, they can see the force of an illustration drawn from the books of Moses. The case of Abraham furnishes an admirable parallel to that of the Galatian Christians who are hoping to be saved by adding legal observances to faith in Christ. Thus Abraham attempted to secure the promised blessing by the fleshly expedient of taking a slave girl in marriage in addition to Sarah his wife; but his real heir proved to be not the child of the slave girl but the son of the freewoman. The child of the slave was rejected; the child of the freewoman obtained the inheritance. So those who trust in Christ are the true sons of god, not those who seek His blessing by placing themselves under bondage to the law. The promised inheritance can be received by faith alone. — The Episitle of Paul to the Galatians, by Charles R. Erdman, page 92.
Hagar and Sarah typically represent the two covenants of law and of grace. “One from Mount Sinai, bearing children unto bondage, which is Hagar.” The first of these covenants is from Mount Sinai. It was there at the foot of the quaking mountain that the people of God bound themselves to observe the requirements of the law. All those who accepted such bondage are properly pictured as children of Hagar. Thus Hagar rightly stands for Mount Sinai in Arabia, the country to which the literal descendants of Hagar belong. Hagar, therefore, rightly represents “the Jerusalem that now is,” those who are still subject to the law, the existing Judaism, the advocates of which are troubling the Galatian church. This present Jerusalem “is in bondage with her children.” On the contrary, “the Jerusalem that is above is free, which is our mother. “The heavenly Jerusalem, the spiritual city of which all Christians are members, is not under bondage of the law, and all its citizens should claim and maintain the liberty secured by Christ. — The Episitle of Paul to the Galatians, by Charles R. Erdman, page 94.
The law and the gospel cannot coexist. The law must disappear before the gospel. It is scarcely possible to estimate the strength of conviction and depth of prophetic insight which this declaration implies. The apostle thus confidently sounds the death-knell of Judaism at a time when one half of Christendom clung to the Mosaic law with a jealous affection little short of frenzy, and while the Judaic party seemed to be growing in influence, and was strong enough even in the Gentile churches of his own founding to undermine his influence and endanger his life. The truth which to us appears a truism, must then have been regarded as a paradox. — Galatians in the Greek New Testament, by Kenneth S. Wuest, page 134-135.