Kiddushin 54A

חזרנו על כל צדדים של רבי מאיר, ולא מצינו הקדש בשוגג אין מתחלל, במזיד מתחלל.

We reviewed all angles of the opinion of R' Meir, i.e., we have examined all of R' Meir’s statements with regard to consecrated property, and we did not find that he holds that consecrated property is not desacralized if it is misused unwittingly but it is desacralized if misused intentionally.

ומשנתינו בכתנות כהונה שלא בלו, הואיל וניתנו ליהנות בהן, לפי שלא ניתנה תורה למלאכי השרת.

And as for our Mishnah, which indicates that this is R' Meir’s opinion, it should not be understood as R' Meir’s opinion with regard to consecrated property in general, but with regard to a case where a priest betrothed a woman using priestly tunics that have not worn out and that can still be worn during the Temple service. If a priest betrothed a woman with such garments, R' Meir holds that if he did so unwittingly she is not betrothed, since clothes of this kind are not desacralized, and do not become hers. This is because they were initially given on the condition that the priests may benefit from them even when not performing the Temple service, since the Torah was not given to the ministering angels. It is impossible for a priest to wear the garments only at the moment he is performing the service and at no other time. Therefore, these garments are desacralized only if he intended to desacralize them.

תא שמע: כתנות כהונה שבלו מועלין בהם, דברי רבי מאיר. מאי לאו אפילו לא בלו? לא, בלו דוקא.

The Talmud raises a difficulty with Rav’s statement. Come and hear: With regard to priestly tunics that have worn out, one misuses property consecrated to the Temple by using them; this is the statement of R' Meir. What, is it not so that this halakha would apply even if they had not worn out, and the tanna wanted to teach the additional halakha that it is still a transgression even after they are no longer fit for use? The Talmud rejects this: No, this halakha applies specifically to garments that have worn out. Since these cannot be used by priests, the permission to use them for non-sacred purposes lapses, and they are like other consecrated property that is subject to the halakhot of misuse.