Does divorce occur if I swore by it that I would not teach a student, thinking that he was trying to evade me, then I taught him because I found him waiting for me?

If an oath of divorce is sworn due to a reason, and then that reason is found to be non-existent, scholars differ on whether the oath is broken. Some meticulous scholars, such as Ibn Taymiyyah, held that divorce does not occur in this situation, because a person might refrain from something for a reason that later ceases to exist, or swear an oath believing something that turns out to be otherwise. Based on this, the questioner is not bound by anything regarding teaching the student after the reason for which he swore the oath has ceased to exist, while noting that swearing an oath of divorce is impermissible.