Not a teacher.
What kind of school was it? A religious one? My best guest is the time before prayers was spent in a leisure fashion with everybody allowed to do their own thing but this guy was punished for his late arrivel to spend his time before the prayers by studying instead of playing, reading, doing his own thing etc.. Well, it sounds a little bit morbid but maybe someone else will throw a better or different light on what you want to know.
Interested in Language