Siman 543

Any melacha that is forbidden for one to do himself on Chol HaMoed—it is forbidden to tell a non-Jew to do it, as we have learned in a Baraita (12a). The general rule of the matter: Anything that he may do—he may tell a non-Jew and he does it, and anything that he may not do—he may not tell a non-Jew to do it. And so too regarding commerce: Anything that is forbidden for himself—is forbidden through a non-Jew. And the reason is simple: Since the primary reason for the prohibition of commerce and melacha is so that they should delight in the joy of Yom Tov and engage in Torah, as I have written in siman 539 in the name of the Yerushalmi, if so, if we were to permit it for him through a non-Jew—he would be preoccupied on the Moed as on weekdays. For what difference is it to me if he himself does it, or if his agent does it? Ultimately, the preoccupation is upon him.

And there is a matter in which chol hamoed is more stringent than yom tov. How so? For example, a non-Jew who accepted a contract to construct a building for an Israelite: within the techum—it is forbidden, and outside the techum—it is permitted, provided there is also no other city within the techum of the building, as I have written above in siman 244. But on chol hamoed—even in such a case it is forbidden. And the reason: since on Shabbat and yom tov it is forbidden to go outside the techum—there is no concern that Israelites will see that they are building the house of so-and-so on Shabbat and yom tov. This is not the case on chol hamoed, when they are able to go outside the techum—it is forbidden because of marit ayin. Therefore, there is no distinction between within the techum and outside the techum.

The Tur wrote that even ex post facto, when the house was built through a prohibition by a non-Jew—it is proper to be stringent that they should not enter it. Thus far his words. That is to say: according to the law it is permitted, but it is proper to be stringent (Beit Yosef). And there is one who wrote that according to the law it is forbidden (Bach), but it is not so (Taz). However, when he gave him work with detached items before the Moed, to perform it during the Moed inside the house of the non-Jew and as a contractor, and he did not explicitly designate for him that he should perform it specifically during the Moed—it is permitted. And it is permitted to give a non-Jew any work, even attached to the ground, as a contractor or as a day laborer before the Moed, and to stipulate with him that he should perform it specifically after the Moed. And even during the Moed—he may hire him to perform it after the Moed. But when he hires him during the Moed—he should be careful not to measure, weigh, or count in the manner that he does on a weekday, but rather he should only make a transaction with him. And for a Jew it is also permitted in such a case, except that regarding a non-Jew there is a greater novelty, even though there is reason to fear that he will not obey and will perform it during Chol HaMoed. Nevertheless, even if he transgressed and performed it during Chol HaMoed—it is permitted, since he stipulated with him to perform it after the Moed. And he also does not need to protest his action (Magen Avraham). But in a matter publicized to the masses—he must protest. (And the Magen Avraham wrote in subsection 1, that for the sake of a mitzvah it is permitted to tell a non-Jew to perform work during Chol HaMoed, see there. And it seems to me that this is with detached items and not with items attached to the ground. And even a beit knesset and a beit midrash—it is forbidden to build, and there is a desecration of God's name in this. And if the non-Jew is a sharecropper in his field—he is permitted to work. And see above siman 243, and see Magen Avraham subsection 3.)