The Cave - 18:66
"When Moses said to him, "May I follow you so that you may teach me the enlightening principles of what you have been taught?"
Related:
Ta-Ha/20:40
Remember when your sister went and said, ´Shall I show you someone to take care of him? So We returned you to your mother so that her eyes would be enlightened and she would not grieve. Even when you had killed a man, We saved you from sorrow and put you through various tests. Now you have come back, Moses, after many years among the people of Medina, according to a definite plan.