grand ayatollah sayyed ali hussaini khamenei answers:
q 1)some mujtahids are of the opinion that the people of the book are najis, while some others consider them pure. what is your opinion?
a: it is not established that the people of the book are najis themselves; rather, we consider them as pure by themselves.
q 2)it is generally said that a house built by the hands of non muslims becomes najis and performing prayer in it is makrūh. is this correct?
a: performing prayer in such a house is not makrūh.
q 3): what is the rule pertaining to working for jews, christians, and other non-muslims, and taking wages from them?
a: there is no objection to doing so by itself, provided the work is not among the ḥarām works or detrimental to the general interests of islam and muslims.
q 4): studying abroad necessitates contact and association with non-muslims. in this case, what is the rule concerning taking food prepared by them (after ascertaining that it does not contain prohibited items such as the meat of an animal which is not slaughtered ritually) if there is a possibility that the non-muslim’s hand have touched the food in the presence of wetness?
a: the mere possibility that the non-muslim’s wet hand have touched it is not sufficient for creating an obligation for refraining from it. rather, unless one is sure that such contact has occurred, it is considered pure. further, if the non-muslim is among the people of the book, he is not intrinsically najis, and if his wet hand touches something, it does not render it najis.