What is the ruling on someone who swore an oath to his shaykh concerning something, while he meant something else?

The fundamental principle regarding an oath is that it is based on the intention of the one taking the oath, unless the subject of the oath pertains to the rights of others. So, if the swearer intends something that the oath can reasonably bear, their oath is directed to that intention, whether what they intended is consistent with the literal meaning of the words or contrary to it. Therefore, if you outwardly swore an oath to your shaykh concerning something, but intended something else, you are not considered to have broken your oath, and nothing is binding upon you. This falls under the category of permissible ambiguity (tawriya). However, if you are made to swear an oath concerning a matter related to the rights of another, then the more authoritative opinion is that the oath, in such a case, is based on the intention of the one requesting the oath, and ambiguity (tawriya) will not benefit you.