Genesis 21:10-12 is the original account Paul quotes directly—Sarah's demand to drive out Hagar and Ishmael, applied allegorically here.

John 8:35 contrasts the slave and son in the house—the slave has no permanent place, echoing the expulsion of Ishmael in 4:30.

Romans 8:15-17 expands on the inheritance theme: believers receive the Spirit of adoption as sons and are heirs with Christ, contrasting with the slave son's exclusion.

Judges 11:2 recounts Jephthah being driven out as a son of another woman, denied inheritance — a direct OT parallel to Ishmael's casting out.