Siman 180

Two who are partners in a courtyard and vowed to derive no benefit from one another, if it is not subject to the law of division because there are not four cubits for each one, as has been explained in siman 171, the vow does not take effect and they are permitted to enter it. This is the case whether they vowed against one another or whether one of them forbade a person from the street from his property. The reason is that it is a known matter that one cannot forbid to his fellow anything except his own property and not that of his fellow; and since the courtyard is acquired by each of the partners to walk and use it, how can he forbid it to him? And also regarding another person he cannot forbid it, because he can say: "I am not entering your portion, but rather that of your partner." And even though perforce the one who vowed also has a portion in the courtyard, nevertheless there is bereirah, and we say that the matter is clarified at the time he enters that it is his at this hour, for they acquired it in partnership on this condition: that at the time each one uses it, it shall be his for that hour; and likewise when another person needs it. And it is not only according to those of our teachers who ruled that even in Torah matters there is bereirah [Tosafot Temurah 30a, and the Rosh and the Ran in the fifth chapter of Nedarim in the name of Ri, the author of the Tosafot], for that would be well understood; but even according to the majority of our teachers, for we hold that in Torah matters there is no bereirah, and so we hold, nevertheless in this case we say there is bereirah. For this bereirah is not similar to all other cases of bereirah in the world, for in all other cases of bereirah in the world there is a complete doubt until the time it is clarified, but here the essence of the matter was clarified from the first moment at the time they acquired the courtyard—that at the time each one uses it, the courtyard shall be his—it is only that the time was not clarified then as to when he would use it, and at the hour he uses it, the time is clarified, but the essence of the matter was clarified already. Therefore, we say bereirah in this case [Ran ibid.]. And this rule that a person from the street is permitted to enter when one of them forbade him applies specifically when that person from the street enters for the need of the second partner, whether he needs the partner or the partner needs him; but not for the need of the partner, one of them certainly has the power to forbid him. And some say that even when he is needed by the partner, there is no permission in the matter since it is not for the benefit of his partner [Shach Yoreh Deah siman 226 and Bach ibid.].

But when the courtyard is subject to the law of division, we do not rely on this berirah, since they can compel division, the neder takes effect, and they are forbidden from entering it when they prohibited one another; and they shall divide it and each shall enter his own. And all the more so when one of them prohibited a person from the street, that he is forbidden from entering it even when he enters for the need of the second partner [ibid.]. And some say that another may enter when he enters for the need of the partnership even if it is subject to the law of division [Tur]. And in that which is not subject to the law of division, another may enter even for his own need [Taz ibid.]. And the reason is that when it is not subject to the law of division, the neder does not take effect at all, and he can say to him, "I am not entering into yours but into your fellow's." And in that which is subject to the law of division, granted that the neder takes effect for the reason that since he can divide we do not rely on berirah, this is regarding themselves, as they have the power to compel one another, but for one from the street, division is not relevant, and therefore when the second partner needs him, we rely on berirah. But to enter for his own need is forbidden; since it is subject to the law of division, he can prohibit it when he enters for his own need [ibid.].

And such is the law regarding two people who have a place in the beit haknesset and forbade it one to the other: if it is not subject to the law of division—meaning that the place does not hold two people—the neder does not take effect. If it is subject to the law of division, the neder takes effect. And similarly, if he said, "my portion shall be hekdesh to you," it is like a neder, for since he said "to you hekdesh," his intention was to forbid it to him. But if he did not say "to you," we say that he only intended that it should be hekdesh for the poor and not to forbid it to him. Nevertheless, if he says that his intention was to forbid it to him, we act according to his explanation, as is written in Yoreh Deah siman 208. And the same law applies to all similar cases. And similarly regarding movable property in which they are partners: if they are subject to the law of division, they can forbid them one to the other, and if not, they are permitted.

When both of them prohibited one another by vow, they are forbidden to place therein an oven, stoves, a mill, or chickens, even if it is not subject to the law of division, for partners may protest one another regarding these matters, as I wrote in siman 161. And even though, ordinarily, partners are not particular with one another regarding these matters, as I wrote in siman 140, nevertheless, in the case of one prohibited from benefit, they are certainly particular and they are forbidden. And if one of them was prohibited from benefit from his fellow, he is forbidden from placing an oven, stoves, a mill, or chickens, and he is forbidden to enter it if it is subject to the law of division, while his fellow is permitted. And it is not specifically these usages, but rather any usage that fills the entire courtyard, such as spreading out fruits and the like, they are forbidden [Shach there].

Our teachers, of blessed memory, penalized the one who vows, such that he must sell his portion even when it does not possess the minimum size for division, for we concern ourselves that the one prohibited by the vow might use it and violate the vow. And some say that when it does not possess the minimum size for division, such that it is permitted to enter the courtyard, we do not compel him to sell his portion; and we only compel when it possesses the minimum size for division and they wish to divide, or through the rule of "buy it or I will buy it" when it does not possess the minimum size for division, we do not compel [Bach there]. And some say that even when they prohibited one another, we compel them to sell or to divide so that they do not stumble. And some say that when both of them are prohibited, we do not concern ourselves with a potential pitfall, for specifically when only one of them is prohibited we concern ourselves that upon seeing that the second is permitted, he too will stumble; but not when both of them are prohibited [Ran, beginning of chapter 5 of Nedarim]. And when do we compel him to sell his portion? When he prohibited it with the language "my courtyard," for then after he sells, the prohibition is removed. But if he said, "This courtyard shall be prohibited to you by a vow," there is no benefit in his selling it, for even after its sale it remains prohibited, as I have written in Yoreh Deah siman 216, see there.

A husband who prohibited benefit from himself to others, they are also prohibited from the nichsei melog of his wife, and it is not similar to a partner who made a vow against someone from the market, for there the reason is due to bereirah as has been explained, which is not the case with nichsei melog; and since he consumes the fruits, it is within his power to prohibit them, as written in Yoreh Deah siman 226, see there.