Does an oath to not exaggerate in hosting a guest become binding, and is preparing what is befitting for the guest considered a breach of this oath, and does the oath take effect if the sworn-upon matter does not follow the قسم (oath/vow)?

The guest's oath is binding if he swore by God that you should not burden yourself with hospitality, and you do not break your oath by violating what your guest swore by; rather, he breaks his oath. However, if you swore an oath and did not mention the object of the oath, then the oath is not binding due to the absence of one of its pillars, which is the object of the oath, and nothing is binding upon you then.