It is purported that Rasulullah (sallallahu alayhi wasallam) had given the monks and priests of St Catherine Church in Mount Sinai a covenant to guara

Answer

If there is no corroboration from the Muhadditheen or the Mutaqaddimeen Fuqaha for the covenant, then obviously it will be a forgery. If there is no reference for it in any of the authentic sources of the Shariah, then its authenticity will not be established simply on the basis of acceptance by the Ottoman Sultans whose policies were generally dictated by political expediencies.

The monastery will be subjected to the rules as stated in the kutub of Fiqah, and as applicable to the Zimmis. It is possible that the Sultans had accorded a different and special treatment to the monastery on the basis of political considerations in the same was as they had done regarding the primary cross which is housed in the Jerusalem temple. Since this particular cross was an extremely valuable and prized item for the Christians, it was captured and held in Muslim custody, but not destroyed whereas intelligence and Imaan demanded its destruction. Even Salahuddin held it and used it as a bargaining chip when peace was entered into with Richard.

Since there is no Islamic rule any where in the world today nor will there be in the foreseeable future, discussion on this issue is merely academic. Islamic rule on a global scale will return with the advent of Imaam Mahdi (alayhis salaam). He will then decide the fate of the monastery.