Genesis 16:15
13 So Hagar named the Lord who spoke to her, “You are the God who sees me,” for she said, “Here I have seen one who sees me!” 14 That is why the well was called Beer Lahai Roi. (It is located between Kadesh and Bered.) 15 So Hagar gave birth to Abram’s son, whom Abram named Ishmael. 16 (Now Abram was eighty-six years old when Hagar gave birth to Ishmael.)
Galatians 4:24
23 But one, the son by the slave woman, was born by natural descent, while the other, the son by the free woman, was born through the promise. 24 These things may be treated as an allegory, for these women represent two covenants. One is from Mount Sinai bearing children for slavery; this is Hagar. 25 Now Hagar represents Mount Sinai in Arabia and corresponds to the present Jerusalem, for she is in slavery with her children.
Notes and References
"... Galatians 4:21-31 reveals the unexpected working of this ecclesiocentric hermeneutic. When Paul announces that the story of Abraham, Sarah, and Hagar is an allegory (Galatians 4:24), the reader, conditioned by Paul's earlier adamant identification of Abraham's seed with Christ (3:16), expects a Christological reading of the patriarchal narrative. But Paul's allegorical reading fails to execute the anticipated identification of Isaac-Abraham's seed who was offered up as a sacrifice-with Jesus Christ. Instead, Paul reads Isaac as a prefiguration of the church: "Now we, brethren, like Isaac, are children of promise" (Galatians 4:28). The Christian community, as "children of the free woman" (Galatians 4:31), constitutes the antitype, the fulfillment of the figure, the true meaning of Scripture. Christ is not even mentioned in Paul's interpretation. What are we to make of this state of affairs? I contend that this Galatians allegory is no anomaly; rather, it discloses an essential aspect of Paul's approach to Scripture ..."
Hays, Richard B. Echoes of Scripture in the Letters of Paul (pp. 86-87) Yale University Press, 1989