Charles Spurgeon Commentary Galatians 3:23-25

"But before faith came, we were kept in ward under the law, shut up unto the faith which should afterwards be revealed. So that the law is become our tutor [to bring us] unto Christ, that we might be justified by faith. But now faith that is come, we are no longer under a tutor." — Galatians 3:23-25 (ASV)

But before faith came, we were kept under the law, shut up unto the faith which should afterward be revealed. Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. But after that faith is come, we are no longer under a schoolmaster.

The apostle is not speaking of a schoolmaster, as we understand that word; but of the slave or servant who took the boys to school, watched over them in school and out, and even used the rod if occasion demanded.