Nedarim 91

ושניהם אסורים להעמיד ריחים ותנור ולגדל תרנגולים

AND BOTH ARE FORBIDDEN TO SET UP A MILL-STONE OR AN OVEN OR BREED FOWLS THEREIN.<span class="x" onmousemove="('comment',' R. Eliezer b. Jacob admits this, for joint owners can object to this. Consequently, if they do not, each benefits by the permission of the other. ');">¹</span>

היה אחד מהם מודר הנאה מחבירו לא יכנס לחצר רבי אליעזר בן יעקב אומר יכול הוא לומר לו לתוך שלי אני נכנס ואיני נכנס לתוך שלך וכופין את הנודר למכור את חלקו

IF [ONLY] ONE WAS FORBIDDEN BY VOW TO BENEFIT FROM THE OTHER, HE MAY NOT ENTER THE COURT. R. ELIEZER B. JACOB SAID: HE CAN MAINTAIN, 'I AM ENTERING INTO MY OWN, NOT INTO YOURS.' HE WHO THUS VOWED IS FORCED TO SELL HIS SHARE [OF THE COURT].<span class="x" onmousemove="('comment',' For since he may enter, but not the other (this being taught on the view of the Sages), the second, in resentment, might enter none the less in disregard of the vow. ');">²</span>

היה אחד מן השוק מודר באחד מהם הנאה לא יכנס לחצר רבי אליעזר בן יעקב אומר יכול לומר לו לתוך של חבירך אני נכנס ואיני נכנס לתוך שלך

IF A MAN FROM THE STREET WAS FORBIDDEN BY VOW TO BENEFIT FROM ONE OF THEM, HE MAY NOT ENTER THE COURT. R. ELIEZER B. JACOB SAID: HE CAN MAINTAIN, 'I ENTER YOUR NEIGHBOUR'S PORTION, AND I DO NOT ENTER INTO YOURS. IF ONE IS FORBIDDEN BY VOW TO BENEFIT FROM HIS NEIGHBOUR, AND THE LATTER POSSESSES A BATH-HOUSE OR AN OLIVE PRESS LEASED TO SOMEONE IN THE TOWN, AND HE HAS AN INTEREST THEREIN, HE [THE MUDDAR] IS FORBIDDEN [TO MAKE USE OF THEM]; IF NOT, HE IS PERMITTED. IF A MAN SAYS TO HIS NEIGHBOUR, 'KONAM, IF I ENTER YOUR HOUSE', OR 'IF I PURCHASE YOUR FIELD,' AND THEN [THE OWNER] DIES OR SELLS IT TO ANOTHER, HE IS PERMITTED [TO ENTER OR BUY IT]; [BUT IF HE SAYS.] 'KONAM, IF I ENTER THIS HOUSE, OR 'IF I PURCHASE THIS FIELD,' AND [THE OWNER] DIES OR SELLS IT TO ANOTHER, HE IS FORBIDDEN.

המודר הנאה מחבירו ויש לו מרחץ ובית הבד מושכרין בעיר אם יש לו בהן תפיסת יד אסור אין לו בהן תפיסת יד מותר

<b><i>GEMARA</i></b>. The scholars propounded: They differ when they interdicted themselves by vow. But what if each imposed a vow upon the other? Do we say, they differ [only] in the former case, but that in the latter the Rabbis agree with R. Eliezer b. Jacob, since they are involuntarily prohibited;<span class="x" onmousemove="('comment',' For if they voluntarily interdict themselves of all benefit, it may be maintained that each thereby renounces also his share, which is inseparable from his partner's. But when each forbids the other, it may be argued that neither can prohibit that which the other enjoys in his own right. ');">³</span>

האומר לחבירו קונם לביתך שאני נכנס ושדך שאני לוקח מת או שמכרו לאחר מותר קונם בית זה שאני נכנס שדה זו שאני לוקח מת או שמכרו לאחר אסור:

or perhaps the Rabbis dispute even in the latter case?<span class="x" onmousemove="('comment',' For the prohibition arises because in their opinion it is impossible to distinguish between the portions belonging to each. ');">⁴</span>

<big><strong>גמ׳</strong></big> איבעיא להו בנדרו פליגי הדירו זה את זה מאי מי אמרינן בנדרו הוא דפליגי אבל בהדירו זה את זה מודו ליה רבנן לראב"י דכי אנוסין דמו או דילמא אפילו בהדירו זה את זה פליגי רבנן

Come and hear: IF [ONLY] ONE WAS FORBIDDEN BY VOW<span class="x" onmousemove="('comment',' Muddar is the hofal, and implies that the vow was imposed upon him by another. ');">⁵</span>

ת"ש היה אחד מהן מודר הנאה מחבירו ופליגי רבנן תני נדור מחבירו הנאה

TO BENEFIT FROM THE OTHER&nbsp;… and the Rabbis dispute it! — Learn, forbade himself from his neighbour.<span class="x" onmousemove="('comment',' Nadur, passive Kal. implies self-imposed. No emendation is really made in the Mishnah, but the Talmud answers that muddar may be synonymous with nadur, self-imposed. ');">⁶</span>

הכי נמי מסתברא דקתני סיפא וכופין את הנודר למכור את חלקו אי אמרת בשלמא דנדר הוא היינו דקתני כופין אלא אי אמרת דאדריה אמאי כופין אותו הא מינס אניס

This is logical too, for the second clause states: NOW, HE WHO THUS VOWED IS FORCED TO SELL HIS SHARE OF THE COURT. Now, this is reasonable if the vow was self-imposed: hence he is compelled. But if you say that a vow was imposed against him, why is he compelled. Seeing that the position is not of his making?<span class="x" onmousemove="('comment',' Lit., 'surely he is under constraint'. I.e., it is equitable to force him to sell, if as a result of his own vow he may come to transgression, but not otherwise. ');">⁷</span>

אמר רבה אמר זעירי

Rabbah said in Ze'iri's name: