Genesis 21:10 shows Hagar's son cast out as a slave's child - an OT illustration of a slave's temporary place.

Romans 8:15-17 expands on adoption as sons, contrasting the spirit of slavery with the Spirit of sonship, and adds inheritance as heirs.

Galatians 4:4-7 directly parallels the slave/son contrast, explaining adoption and heirship through Christ's redemption.

Galatians 4:30 applies the same OT example to contrast slave and free children - reinforcing Jesus' distinction.

Galatians 4:31 concludes believers are children of the free woman - directly parallel to sons belonging forever.

Hebrews 3:6 presents Christ as the Son over God's house, and believers as the house, linking to the son's permanent place.

In Genesis 21:14, Hagar the slave is cast out — illustrating the slave's temporary place that Jesus contrasts with the son's permanence.

Hebrews 3:5 portrays Moses as a servant in God's house, contrasting the servant role with the son's permanent authority.

In Deuteronomy 34:5, Moses the servant dies — even the greatest servant is temporary, unlike the Son who remains forever.

In Deuteronomy 15:12, a Hebrew slave goes free after six years — showing the temporary nature of bondage that Jesus uses to contrast with the son's eternal place.

In Ezekiel 46:16, a prince's gift to his sons is a permanent inheritance — matching the son's permanent status Jesus speaks of, contrasting with the slave.