Jerome, Commentary on Galatians, [J.P. Migne, Editor]. Patrologiae Tomus XXVI. Paris: D’Ambroise, Pres La Barriere D’Enfer, ou Petit-Montrouge, 1845. pp. 307-438.
In Galatians 4:21, Paul asks the Galatians if hey were not hearing the law. Jerome notes that this is common language. It is not that they do not audibly hear the law, but that they are bad at paying attention to it implications (Jerome, Galatians, 387). Paul’s subsequent statements about the difference between Iaac, the child of promise, and Ishmael, the child of the flesh, are a challenge. Jerome observes that, although he is not the child of promise, God does make some promises to Ishmael. He then compares the two children to the stars and the sun. God’s promises to Ishmael shine like the stars, but Jerome observes that even the bright stars are not visible in daylight (Jerome, Galatians, 388). The promise and blessing on Ishmael is not o the same nature as that about Isaac. Jerome then extends his application of the promise to Isaac beyond the bounds of his physical descendants to say that all “who do the works of Abraham, are born of Abraham” (Jerome, Galatians, 389, personal translation). Jerome does then tie the “children of Abraham” to those who are the freeborn children through Christ. This connection sees the children of Abraham as an allegory of the world’s population, some free through Christ, and some in bondage to sin. Verse 24 affirms that the discussion is purposely allegorical. Jerome takes this opportunity to observe that Paul makes numerous references to secular literature, not only making quotations but also using classic figures of speech and rhetoric. Jerome’s conclusion is that Paul is well versed in secular literature (Jerome, Galatians, 390).
Paul’s argument intensifies as, in verses 25-26, he ties the two testaments directly to the two mothers in the passage. Hagar refers to the law and Sarah to the gospel. Jerome particularly relates the gospel to Jesus, specifically in his being born of the virgin, someone who, like Sarah, could not give birth (Jerome, Galatians, 390). Jerome continues to expand on the differences between law and gospel, Sina and Jerusalem, Moses and Jesus, the Old and New Testaments (Jerome, Galatians, 391).
Jerome speaks forcefully against Marcion and the Manichaeans, who take Paul’s statement of allegorical interpretation to refer to all of Scripture, which he alleges they never read (Jerome, Galatians, 391). At its heart, Jerome is concerned that the allegory must remain interpreted as Paul gave it in the passage. It is not a matter of individual choice.
Verse 27 reflects on the fact that the Holy Spirit gives us reason for rejoicing in Christ, not in ourselves. Jerome then emphasizes that the Church was barren without Jesus. God’s promises were for Isaac, the child of promise, with the promise fulfilled in the death of Christ (Jerome, Galatians, 391). The bottom line, in verse 28, is that we Christians are the children of Isaac. The promise is central (Jerome, Galatians, 392). Those who are consumed by the flesh are children of the slave woman.
Verses 29-31 conclude Paul’s present argument. The slave woman and her child are to be cast out. Jerome repeats this claim, emphasizing it is the correct conclusion even though Ishmael was born first, that he and Isaac would have played together, and that Paul, writing this, was a notably faithful Pharisee (Jerome, Galatians, 392). Jerome does point out the fact that trust in the promises of God is what matters. However, in Jerome’s time, as in Paul’s and ours, Christians typically look up to those who are dedicated to keeping the Law, rather than trusting in God’s promises (Jerome, Galatians, 393).