Is a mistake in some matters considered a violation of the aforementioned oath, which includes striving for God's pleasure and preserving His religion, whether stated with intention or not?

It is not legislated for students to take an oath during the morning assembly, due to the hardship it would impose on them if they were to break their oath and not offer expiation. The basis of an oath rests on the intention of the one swearing it. If he intends by his oath something that it can bear, the oath is directed towards that. If the one swearing the oath has no intention, one refers to the reason for the oath, then the custom, then the wording. Given the generality of the wordings and the variation in their fulfillment, it is safer to offer a single expiation if one breaks multiple oaths concerning one thing and has not yet expiated. So, whoever repeats an oath whose subject is the same action, then a single expiation is due. However, if one has expiated for the first oath and then repeats the oath, a second expiation is due if he breaks it. If one repeats oaths concerning multiple actions, then an expiation is due for each oath. The expiation for an oath is: feeding ten needy persons, or clothing them, or freeing a slave. If one cannot find these, then fasting for three days.