Avodah Zarah 52B

כיון דאיסורה בטיל, טומאה נמי בטלה. כי קא מיבעיא ליה תקרובת לעבודה זרה של אוכלין, מאי? כיון דאיסוריה לא בטיל, כדרב גידל, טומאה נמי לא בטלה, או דלמא איסור דאורייתא לא בטיל, טומאה דרבנן בטיל? תיקו.

as, since its prohibition is nullified, its impurity is also nullified. When he raises the dilemma, it is only with regard to an offering consisting of food brought in idolatrous worship. What is the halakha? Does one say that since its prohibition is not nullified, in accordance with the statement of Rav Giddel, who teaches that the prohibition that takes effect with regard to offerings brought in idolatrous worship is never nullified, therefore the impurity is also not nullified? Or perhaps only their prohibition, which is by Torah law, is not nullified, but their impurity, which is by rabbinic law, is nullified. The Talmud concludes: The dilemma should stand unresolved.

בעא מיניה רבי יוסי בן שאול מרבי: כלים ששימשו בהן בבית חוניו, מהו שישתמשו בהן בבית המקדש?

§ R' Yosei ben Shaul asked R' Yehuda HaNasi: With regard to vessels that were used in the temple of Onias, what is the halakha with regard to using them in the Temple?

וקא מיבעיא ליה, אליבא דמאן דאמר בית חוניו לאו בית עבודה זרה היא, דתנן: כהנים ששימשו בבית חוניו לא ישמשו במקדש שבירושלים, ואינו צריך לומר לדבר אחר.

And he raised this dilemma according to the opinion of the one who says that the temple of Onias was not a temple of idol worship. As we learned in a Mishnah (Menaḥot 109a): Priests who served in the temple of Onias may not serve in the Temple that is in Jerusalem, and needless to say, those priests who served in a temple of something else, i.e., idol worship, may not serve in the Temple in Jerusalem. This distinction indicates that the temple of Onias was not a temple of idol worship. It was used for the service of God, but it violated the prohibition against sacrificing offerings outside of the Temple in Jerusalem.