Avodah Zarah 21B

וסתמא כרבי מאיר, דאי רבי יוסי, בכל דוכתא מוגרי.

And this unattributed opinion in the Mishnah is in accordance with the opinion of R' Meir. As, if you say that this ruling is in accordance with the opinion of R' Yosei, that cannot be, since he holds that in every place one may rent a house to a non-Jew, including Eretz Yisrael.

ובכל מקום לא ישכור וכו׳. תניא: רבן שמעון בן גמליאל אומר: לא ישכור אדם מרחצו לגוי, מפני שנקרא על שמו, וגוי זה עושה בו מלאכה בשבתות ובימים טובים.

§ The Mishnah teaches: And in every place, one may not rent a bathhouse to a non-Jew, as it is called by the name of the owner. The Talmud notes that it is taught in a baraita that Rabban Shimon ben Gamliel says: A person may not rent his bathhouse to a non-Jew, because it is called by the name of the owner, and this non-Jew uses it for performing prohibited labor on Shabbatot and on Festivals.

אבל לכותי, מאי? שרי. כותי אימר עביד ביה מלאכה בחולו של מועד! בחולו של מועד אנן נמי עבדינן.

The Talmud asks: It is prohibited to rent one’s bathhouse to a non-Jew, but with regard to a Samaritan, what is the halakha? It can be inferred from the lack of mention of a Samaritan that it is permitted. The Talmud asks: Why not say that a Samaritan will perform work in the bathhouse during the intermediate days of a Festival? The Talmud answers: During the intermediate days of a Festival we too perform work and heat bathhouses.

אבל שדהו לגוי, מאי? שרי. מאי טעמא? אריסא אריסותיה קעביד. מרחץ נמי אמרי: אריסא אריסותיה קעביד? אריסא דמרחץ לא עבדי אנשי.

The Talmud further infers: It is prohibited to rent one’s bathhouse to a non-Jew; but with regard to renting one’s field to a non-Jew, what is the halakha? Evidently, it is permitted. What is the reason for this? People know that a non-Jew sharecropper works for his tenancy, not for the Jewish owner. The Talmud asks: But if so, in the case of a bathhouse as well, why not say that the non-Jew sharecropper works for his tenancy, and therefore a Jew should be permitted to rent them to non-Jews. The Talmud answers: People do not usually make this type of arrangement by which a second party works as a sharecropper of a bathhouse. Consequently, it will be assumed that the non-Jew is a hired worker who is working for the Jew.