Kommentar zu Dewarim 7:26

תתעבנו כי חרם הוא, you must treat that silver and gold as if it were an abomination;

ולא תביא תועבה אל ביתך, “and do not bring any abomination into your house.” Our sages derive from this verse indirectly that it is forbidden to rent out one’s house to a pagan as a residence seeing the pagan will introduce various idols into your house. The technical reason why the Jew renting the house to a pagan is transgressing the law is that renting does not confer title of the ground the property is on to the person who has rented the house. Seeing the ground remains the property of the Jew he is held liable (rabbinically) when the pagan practices idolatry in that house (based on Meiri in Avodah Zarah 21). However, we find that some halachic authorities take a more lenient view; these include the Jerusalem Talmud as well as Rabbeinu Chananel, hence our practice of renting houses to Gentiles. Nachmanides takes a more stringent view stating that a responsible person will refrain from renting his house to Gentiles not only in the countries under Catholic rule but also in those under Moslem rule.

V. 26. ׳ולא תביא וגו: dein Haus, der Kreis deines Menschentums, soll frei bleiben von jeder solcher heidnischen Spur. Es ist הרם, es ist dem Vernichtungsbann verfallen, והיית חרם כמהו und welche Seite deines Seins und Wollens du in Beziehung zu ihm setzen oder aus ihm hervorgehen lassen möchtest, würde selbst in tausendster Vermittlung alle Existenzberechtigung einbüßen und dem gleichen Vernichtungsbanne verfallen. כל שאתה מהיה ממנו הרי הוא כמוה, alles, dessen Dasein du dir durch es vermittelst, wird ihm gleich. ע׳׳ז ist תופס דמיו, und nach רמב׳׳ם sind selbst חליפי חליפין אסורים (Aboda Sara 54 b. — Siehe zu Wajikra 25, 5).