4:24 Paul then interpreted these events figuratively. Note that he said the story "contained"an allegory, not "was"an allegory. He acknowledged the historicity of the events. He saw in this story an illustration of the conflict between Judaism and Christianity, nomism and spirituality. He was calling allegory what we refer to as analogy.
"Since the kind of OT exegesis found in this passage is by no means generally characteristic of Paul, the natural inference is that there was a special reason for its use here. The reason is not far to seek: if the Judaizers in Galatia were using a similar kind of argument to persuade the Christians that sonship to Abraham entailed circumcision and observance of the law, it would be especially appropriate for Paul to turn his opponents' own weapons against them."156
"The gospel is the fulfillment of the promise made to Abraham that in him and his offspring all nations would be blessed (cf. 3:8, 16). The law, which was given later, was a parenthetical dispensation introduced by God for a limited purpose; its validity continued only until the promise to Abraham was fulfilled in Christ, and even while it was valid it did not modify the terms of the promise (cf. 3:17-25)."157
4:25 Hagar represents the Mosaic Covenant made at Mount Sinai. Her descendants represent the Israelites who lived in bondage under the Law. Sarah, not mentioned in verse 25, represents the Abrahamic Covenant, and her descendants are free living under the promise.
The earliest identification of Mt. Sinai with Jebel Musa in the Sinai peninsula, the most popular probable site, comes from the writing of Egeria in the fourth century A.D. Perhaps in Paul's day the Sinai Peninsula was part of Arabia.158Another possibility is that the real Mt. Sinai was in ancient (and modern) Arabia, perhaps just east of the Gulf of Aqabah.
"Paul is apparently viewing Arabia as the land of Hagar's descendants and the land of slaves; it was not the holy land that God gave Israel."159
4:26 Hagar also represents old Jerusalem, enslaved under Rome and the Mosaic Law, which Paul did not mention in verse 26. Sarah represents the heavenly city of Jerusalem, the final destiny of departed believers, which is free. She is also the mother of all true believers.
The main features in this analogy are as follows.
Hagar is the bond women Sarah is the free woman
Ishmael was born naturally Isaac was born supernaturally
The old covenant The new covenant
The earthly Jerusalem The heavenly Jerusalem
Judaism Christianity160
4:27 The quotation from Isaiah 54:1 predicted that Israel, which was comparatively barren before the Babylonian exile, would enjoy numerous children in the future. This is probably a reference to the blessings of the millennial kingdom. Paul applied this prophecy to Sarah. She would have greater blessing and more children in the future than in the past, children of the promises, namely all true believers including Christians.
