Galatians 4:2

But is under tutors and governors until the time appointed of the father.

Cross-reference

In Galatians 4:7, the result is revealed: no longer a slave but a son and heir — the transition from guardianship to full sonship.

In Galatians 3:24, the same 'guardian' metaphor shows the law served as our tutor until Christ, paralleling the heir's guardians until the appointed time.