Roman adoption law behind "adoption to sonship" (8:15, 23)

Says Believers "received the Spirit of adoption to sonship" (8:15, BSB) and "wait eagerly for our adoption as sons, the redemption of our bodies" (8:23). God calls Israel "My firstborn son" (Exod 4:22), and of Israel Paul says, "Theirs is the adoption as sons" (9:4).

Gaius (second century AD, later than Paul) says adopted children come under paternal power just as natural children do. Adoption took two forms: adrogation, by authority of the people, for a person independent of any father, and adoption by a magistrate’s command, for one still under a father’s power (Inst. 1.97–99). In adrogation the adoptee’s own children passed with him under the new father’s power (1.107). Adopted children counted with natural ones as the father’s own heirs (sui heredes) on intestacy (3.1–2). Giving a son in adoption took three mancipations, each an imaginary sale before at least five citizen witnesses, and a claim before the praetor (1.119, 134). The adrogated man’s property passed to his adopter, and his own debts lapsed at civil law, though the praetor let creditors sue as if his status had not changed (3.83–84). Octavian took the name Gaius Caesar under his great-uncle’s will (Suetonius, Aug. 7).

Lyall argues that Jewish law had no such notion of adoption. The claim is disputed: Gen 48:5, Exod 2:10 and Esth 2:7 are sometimes read as adoptions.

Uncertain How far Paul’s image draws on Roman law rather than on Israel’s sonship is uncertain; this note takes no lean and leaves its meaning to the exegetical notes.