Resources for Nedarim 88

The משנה says that if a father-in-law makes his son-in-law אסור in all his נכסים and now wants to give his daughter some money, he must say “על מנת שאין לבעליך רשות בו”. The פּורת יוסף asks what seems to be a very strong question: you can’t force someone to be קונה something against their will. For example, if someone puts chometz on your doorstep on Pesach, you won’t violate בל יראה because you have no intention to be קונה the chometz. Just because someone puts something in your רשות doesn’t mean you are forced to acquire it. If so, in our case, the husband does not have to acquire something that will cause him to violate a נדר. So why can’t the father simply give something to his daughter and the son-in-law won’t acquire it since he doesn’t want it?! Interestingly, the ט"ז in יו"ד סימן רכ"ב ס"ק ג assumes that the husband does not violate the לאו even if he does acquire it, as long as he doesn’t get benefit from it. He asks therefore that the father should be able to give his daughter money and the son-in-law will surely be careful not to get benefit from the פּירות because he knows its אסור so why does the husband have to say על מנת שאין לבעליך רשות בו? He answers that the way it works is that husband actually acquires the item first and then gives it to his wife (automatically) so he is considered getting הנאה it by being able to give it to his wife.

There is another question related to the above. There is a מחלוקת ראשונים as to whether one can technically own something that is אסור בהנאה to them. The רשב"א famously says in a תשובה (חלק א סימן תר"ב) that one cannot acquire something if it is אסור בהנאה. He is talking about a case where a woman made herself אסור בהנאה from a certain man’s property and then he gave her כסף קידושין and he says she isn’t קונה because its אסור בהנאה. The ר"ן on דף מ"ז and דף פּ"ה disagrees and holds you do own it unless you yourself made it אסור בהנאה in which case we assume you wanted to be מפקיר it. If you hold like the רשב"א then the husband here cannot acquire it from his wife anyway since it is אסור בהנאה to him so why can’t the father just give it to his daughter without saying על מנת שאין לבעליך רשות בו?! The מחנה אפרים in הלכות זכיה מהפקר סימן ד brings this as a proof to the ר"ן that one can own something that one cannot get benefit from. In a related subject, the מחנה אפרים also quotes the רשב"א as saying that if you are מודר הנאה from someone then they can’t give you a לולב because you can’t acquire something אסור בהנאה so it won’t be considered לכם. The מנחת שלמה on our דף wonders whether a woman would be able to be יוצא מצות לולב if someone other than her husband gave her a לולב since her husband will automatically owns anything she owns and maybe its not לכם! He answers that the husband only owns the פּירות but the גוף הלולב is fully owned by her and that is enough to be considered לכם. He also says that if you give it to her as a מתנה על מנת להחזיר then the husband isn’t קונה it at all.