daf bit: Nedarim 46

[cellio]

Precision matters. If one makes a vow of abstinence to his neighbor, vowing not to enter "your house" or benefit from "your field", and then the neighbor dies or sells the house or field, then the vow no longer applies (it's no longer "your" property). If, on the other hand, one vows concerning "this house" or "this field", that's forever. So says the mishna, and the g'mara here does not conclude otherwise. (46a)

I don't see any discussion here about whether "your house" (etc) follows the owner -- if you make such a vow and then your neighbor moves, are you forbidden to enter his new home (since you are no longer barred from the old one)? Or does a vow only apply when the object of said vow was known at the time it was made?

Comments

[dvarin.livejournal.com]

It seems like the consistent thing would be that you are, since "your house" continues to exist until the death of the person. It just does so in a different location.

...relatedly, shouldn't "this house" be prone to that as well? In the case that the house itself is moved?

[cellio]

I'm not sure how the rabbis would handle the house being moved. When you move a house, as I understand it, you're moving the above-ground construction onto a new foundation, so it's mostly the same house but not entirely -- so how would that factor in? How far down does "this house" go?

[dvarin.livejournal.com]

Hm. I originally thought of the "over 50%" rule that gets used for mixes sometimes, but a house isn't a uniform mixture so perhaps house identity attaches to some specific central part, like the hearth.

Another thought which may or may not be interesting: how does all this interact with an eruv? From your previous explanations that seems to be a means for defining a common private area that includes an entire neighborhood by merging all the households in it. If someone vows not to enter "your house", are they prohibited from the entire eruv'ed area the person lives in?

[cellio]

Another thought which may or may not be interesting:

Mishna: If [two] joint owners made a vow not to benefit from one another, they may not enter the courtyard (which belongs to both). R. Eliezer b. Yaakov said: each enters into his own (meaning his own share -- he's going to be overruled on this, though). Both are forbidden to set up a mill-stone or an oven or breed fowls therein. If [only] one was forbidden by vow to benefit from the other, he may not enter the court. R. Eliezer (dissents again). (45b)

This doesn't talk specifically about the eiruv, but since the eiruv is based on the principle of the shared courtyard this seems relevant.