Galatians 4:26 identifies the free woman as the Jerusalem above, our mother, continuing and clarifying the allegory introduced in verse 22.

Galatians 3:29 concludes that believers are Abraham's offspring and heirs by promise, setting up the allegory of the two sons in chapter 4.

Genesis 16:2-4 recounts Hagar's conception of Ishmael — the slave woman's son Paul references here.

Genesis 16:15 records Ishmael's birth — the specific event Paul alludes to when mentioning the son by the slave woman.

Genesis 21:1 tells of God's promise to Sarah — the free woman whose son Isaac is the other son in Paul's allegory.

Genesis 21:2 records Isaac's birth — the free woman's son, fulfilling God's promise, as Paul contrasts the two sons.

Genesis 21:10 reports Sarah's demand to expel Hagar and Ishmael — the basis for Paul's later argument about inheritance.

Genesis 21:9 describes Ishmael mocking Isaac — the persecution Paul later links to the flesh versus Spirit conflict.

Matthew 3:9 warns against relying on physical descent from Abraham, reinforcing Paul's point that not all biological children are true heirs.

Romans 9:8 explicitly contrasts children of the flesh and children of the promise, directly paralleling the allegory of Hagar and Sarah.