1) RENTING AND SELLING LAND TO NOCHRIM OUTSIDE OF ERETZ YISRAEL
OPINIONS: The Mishnah states that one is permitted to sell and rent houses to Nochrim in Chutz la'Aretz. The Mishnah limits the allowance to rent a house to a Nochri to when the Nochri's purpose in renting the house is non-residential. If, however, the Nochri intends to reside in the house, then the Jew may not rent it to him since the Nochri certainly will set up an idol in the house, and the Jew will be guilty of transgressing the prohibition of "v'Lo Savi So'evah El Beisecha" -- "You shall not bring an abomination into your house" (Devarim 7:26).
This limitation does not seem to be practiced today, as Jews always lease residential domiciles to Nochrim without inquiring of their idolatrous affiliation. Why, though, is this practice permitted in light of the statement of the Mishnah?
(a) TOSFOS (DH Af) explores the basis for the custom to permit selling and renting houses to Nochrim. He writes that some propose that the allowance is based on the Tosefta (2:3). After the Tosefta makes a statement similar to that of the Mishnah, it says that one nevertheless is permitted to rent stables, storehouses, and inns to Nochrim even if it is known that they will bring their idols into the place. Perhaps the reasoning behind the Tosefta's opinion is that a Nochri brings his idol into stables, storehouses, and inns only occasionally. In contrast, he brings his idol into his residence all the time. The Tosefta means that the prohibition for a Jew to lease a place to a Nochri applies only when the Nochri will bring his idol into the house permanently. Accordingly, today one is permitted to rent a house to a Nochri, because in today's world Nochrim do not keep idols permanently in their homes.
Tosfos does not accept this approach. He asks that perhaps the Tosefta maintains that a Jew should never allow an idol to be brought into a house or building that he owns, even infrequently. The reason why the Tosefta permits a Jew to rent stables, storehouses, and inns to Nochrim is that these buildings are not categorized under the title of "houses" since they are not used for residential purposes.
(b) Tosfos quotes RABEINU CHAIM KOHEN who says that the Yerushalmi is the source for the allowance to lease a home to a Nochri. The Yerushalmi explains that the Mishnah's prohibition against renting a house to a Nochri for residential purposes applies only in a place where the Chachamim permitted only renting, and not selling, a house to a Nochri. Where the Chachamim permitted one to sell a house to a Nochri, one may sell and rent to a Nochri even for residential purposes. Even though the Nochri will bring his idol into the house, the Jew does not transgress the Isur of "v'Lo Savi So'evah El Beisecha" because a house owned by a Jew in Chutz la'Aretz is not considered "Beisecha," fully-owned by the Jew.
Perhaps the intention of Rabeinu Chaim Kohen is as the RA'AVAN (#291) writes. The verse of "Beisecha" refers to places like Eretz Yisrael and Surya where the Jew has exclusive and unconditional ownership of his property. In Chutz la'Aretz, even though the Jew owns the land or the house, he is obligated to pay taxes to the government, and thus his ownership is not called "Beisecha." (See also the explanation of RABEINU TAM, cited by Tosfos to 58b, DH Betzer, for why Terumos and Ma'aseros are not given nowadays.)
Tosfos quotes the RI who asks a number of questions on this explanation. One of his questions is that it is not logical to say that the level of a Jew's ownership in Chutz la'Aretz is less than that of a Nochri's. Tosfos asks further that according to this reasoning, a house owned by a Jew in Chutz la'Aretz should not need a Mezuzah, because the verse which commands the Mitzvah of Mezuzah also says "Beisecha" (Devarim 6:9)! The Halachah, however, clearly requires that a Jew affix a Mezuzah to his home even in Chutz la'Aretz, as the Gemara in Menachos (44a) teaches.
(c) The RI agrees that the Yerushalmi quoted by Rabeinu Chaim Kohen is the source for the allowance to rent houses to Nochrim in Chutz la'Aretz. However, he quotes RABEINU ELCHANAN who gives a different explanation for the statement of the Yerushalmi that renting to Nochrim for residential purposes is permitted in a place where one is permitted to sell houses to Nochrim. Rabeinu Elchanan explains that the verse of "v'Lo Savi So'evah El Beisecha" prohibits only bringing an idol into a place where a Jew actually lives, but not to bringing an idol into a house merely owned by a Jew, but which is not occupied by a Jew. This is similar to the Mitzvah of Mezuzah which, mid'Oraisa, obligates one to affix a Mezuzah only to a house in which he lives, but not to a house which he owns but in which he does not live.
The Ri says that the Mishnah here concurs with this. The Mishnah's prohibition to rent a house to a Nochri in Eretz Yisrael is a Gezeirah d'Rabanan (and not the Isur d'Oraisa of "v'Lo Savi"), which the Rabanan instituted in order to prevent idols from being brought into homes in Eretz Yisrael. In Chutz la'Aretz, the Rabanan were lenient and did not enact this Gezeirah.
(See additional interpretations of the Yerushalmi in TOSFOS RABEINU ELCHANAN.)
(d) The RAMBAN (DH Ha d'Tenan Lo) gives a different explanation for the verse of "v'Lo Savi." He explains that the verse forbids a Jew from bringing an idol into his house only when he does so with intention to benefit from the Avodah Zarah. The Ramban refers to the Gemara in Makos (22a) which derives from this verse the law that one who benefits from an Asheirah tree (a tree designated as Avodah Zarah) is punished with Malkus. This implies that the Torah's intention is that a Jew should not bring an idol into his home in order to derive pleasure from it. Accordingly, even if a Jew brings an idol into his home, he transgresses the Torah prohibition only when he intends to derive pleasure from it in some manner. Bringing an idol into one's one for any other purpose is forbidden only mid'Rabanan.
The Ramban also gives this explanation in his commentary on the verse (Devarim 7:26). This is also the opinion of the RITVA and the RAN.
According to this opinion, the prohibition to rent a house to a Nochri for residential purposes applies only in Eretz Yisrael, where the Rabanan prohibited it in order to uphold the obligation to root out all Avodah Zarah from Eretz Yisrael, as the Ran explains. This stringency does not apply to renting a house to a Nochri in Chutz la'Aretz.
(e) The RA'AVAN (#291) suggests that Nochrim today, in most civilized places, do not actually worship idols, and it is very likely that a Nochri will not bring an idol into his place of residence at all. A Jew may rent a home to a Nochri, relying on the likelihood that the Nochri will not bring an Avodah Zarah into the house. He adds that this allowance applies only in places where the conduct of the Nochrim fits this description (as opposed to certain counties in the Far East, for example, where Nochrim commonly keep idols in their homes). (Y. MONTROSE)
2) HALACHAH: HAVING A NOCHRI BUILD A HOME FOR A JEW ON SHABBOS
OPINIONS: The Gemara states that a Jew is allowed to rent his field to a Nochri because when people see the Nochri working in the Jew's field on Shabbos, they will assume that the Nochri is working on Shabbos in order to increase his own share of the crop. This implies that as long as a Nochri is working for his own interests, he may work for a Jew on Shabbos.
The Gemara implies that as long as the Jew does not tell the Nochri to work on Shabbos, and no onlookers suspect that the Jew told the Nochri to work on Shabbos, the Jew is permitted to have a Nochri work for him on Shabbos. Does this apply to other forms of work (besides agricultural work), such as constructing a house?
(a) TOSFOS (DH Arisa) quotes RABEINU TAM who says that a Nochri is permitted to build a house for a Jew on Shabbos when the Nochri was hired through a "Kablanus" agreement, wherein the Nochri agrees to do a specific job for a set price (in contrast to being paid by the day or by the hour). In the case of the Gemara, the Jew is permitted to let the Nochri work on his land on Shabbos because the Nochri is working for his own benefit, even though the Jew simultaneously benefits by having his land improved. When a Nochri, hired through an agreement of Kablanus to build a house for a Jew, works on Shabbos, people who see the Nochri at work will say that he is working on Shabbos not because the Jew hired him to work then, but because the Nochri himself chose this as the most convenient time to work.
Rabeinu Tam cites further proof for this logic from the Gemara in Shabbos (17b), in which Beis Hillel states that one may give garments to a Nochri launderer to be cleaned before Shabbos, even though the Nochri might choose to clean them on Shabbos.
However, the Gemara in Moed Katan (12a) seems to contradict Rabeinu Tam's explanation. The Gemara quotes Shmuel who says explicitly that a Jew may not hire a Nochri to work for him through Kablanus if the Nochri will do the work within the Techum Shabbos.
Rabeinu Tam explains that the Gemara in Moed Katan does not refer to Shabbos at all. Rather, it refers to an Avel (mourner) who is not permitted to commission a Nochri to do work for him inside the Techum. This follows the opinion there (11b) that some of the laws of an Avel regarding work are more stringent than the laws of Chol ha'Mo'ed. However, such restrictions apply only to an Avel (and their purpose is to ensure that the prohibition against an Avel working be taken seriously). Such restrictions do not apply to Shabbos, because people are much more serious and careful about the laws of Shabbos. Hence, the Chachamim did not prohibit hiring Nochrim through Kablanus who will work for the Jew on Shabbos even within the Techum.
(b) RASHI in Moed Katan (12a), the RI (cited by Tosfos here), and almost all of the other Rishonim maintain that a Jew may not hire a Nochri to build a house for him on Shabbos, even through Kablanus. They explain that having a Nochri work one's field on Shabbos is different, because sharecropping is a prevalent method of business, and thus no one will suspect that the Nochri is working solely for the benefit of the Jew. Construction, on the other hand, often involves workers hired for the day (and not through Kablanus). Onlookers will more readily assume that the Jew hired the workers for the day to work for him on Shabbos.
These Rishonim explain that the Gemara in Moed Katan indeed refers to Shabbos. They refute Rabeinu Tam's proof from the Gemara in Shabbos by saying that when a Nochri launderer cleans the garments of a Jew on Shabbos, this act does not look like Chilul Shabbos; there is no reason for anyone to suspect that the Jew commissioned the Nochri to work for him on Shabbos (see Rashi there). In contrast, a large and extensive project such as the building of a house certainly arouses onlookers' suspicion that the Jew hired the Nochri to work for him on Shabbos.
(c) The Ri takes this view even further and says that a Jew is forbidden to build his house with bricks that were cut on Shabbos by a Nochri, even though the Nochri cut those bricks in the privacy of his own home. He explains that the Halachah follows the view of Rebbi Shimon ben Elazar, cited in the Yerushalmi, who says that when a Nochri works on something that will be attached to the ground, this is tantamount to working on the house in public view. Only if the work is done by the Nochri outside of the Techum of the city is the permitted to benefit from that work.
The Rishonim disagree about the Ri's intention in his stringent ruling. The TUR (OC 244), SEMAG (Lo Ta'aseh 65), HAGAHOS MAIMONIYOS (Hilchos Shabbos 6:40) and others write that a Jew is forbidden to use bricks made by a Nochri on Shabbos inside the Techum. However, RABEINU YERUCHAM (Nesiv 12:82) quotes the Ri's ruling only as a stringency, but not as an Isur. He writes that "there were some Gedolim who were stringent upon themselves...." While the BEIS YOSEF (OC 244) does not agree with any of the possible proofs for Rabeinu Yerucham's approach, in the SHULCHAN ARUCH he does not write that one is forbidden to use the bricks (as the Tur writes), but rather he writes merely that one "should not use them." The BI'UR HALACHAH infers from this wording that the Shulchan Aruch concludes that this is a stringency and not an Isur.
(d) The KOL BO, as cited by the REMA, rules that if the bricks which the Nochri manufactured on Shabbos were not known to have been made for the Jew, then the Jew is permitted to use them for the building. The ELIYAH RABAH, MISHNAH BERURAH and others explain that if the ownership of the building under construction is not known (that is, people do not know that it is owned by a Jew), then, according to the Kol Bo, a Nochri may build it for the Jew on Shabbos.
HALACHAH: In practice, the Halachah does not follow the view of Rabeinu Tam. The Beis Yosef quotes many Rishonim (including Tosfos here) who assert that Rabeinu Tam himself did not rely on this leniency when he built his own house. However, the DARCHEI MOSHE points out that this does not necessarily mean that Rabeinu Tam retracted his opinion; perhaps he merely wanted to be stringent in his own conduct. In practice, all of the Poskim agree that one should not have a Nochri do construction work for him on Shabbos, even when the Nochri is hired through Kablanus. If one already had a Nochri work for him on Shabbos, the Shulchan Aruch says that it is proper to be stringent and not enter the house. However, the Mishnah Berurah (OC 244:20) quotes many Acharonim who rule that if the work was already done, then one may rely on the opinion of Rabeinu Tam and may dwell in the house. (Y. MONTROSE)