Augustine of Hippo

Moses in fact took care to appoint teachers of reading and writing for God's people before they had any written record of God's law. The Septuagint Scripture calls these instructors grammatoeisagogoı́, which is Greek for "bringers-in of letters," because they brought them, in a sense, into their students' minds or perhaps introduced their students to them.

City of God 18.39 ↗

Gregory the Dialogist

Hence Moses, who speaks with God, is judged by the reproof of Jethro, who was of alien race, because with ill-advised labour he devotes himself to the people's earthly affairs: and counsel too is presently given him, that he should appoint others in his stead for settling earthly strifes, and he himself should be more free to learn spiritual secrets for the instruction of the people.

The Book of Pastoral Rule, Part 2, Chapter 7 ↗