Bava Kamma, Chapter 9, Mishnah 10. This Mishnah deviates slightly from the topic of the chapter, as it does not deal with the laws of robbery at all. Since the previous Mishnah dealt with a legal loophole where a person borrows money against a sum he must return, our Mishnah brings a similar loophole in a different area of halachah - the area of vows.
"Ha'omer levno konam i atah neheneh misheli":
A father who says to his son, "Konam i atah neheneh misheli" - forbids him with a vow from benefiting from his property. The meaning is: if you benefit from my property, it is forbidden to you as if it were a sacrifice ("konam" is a substitute term for a sacrifice). This is not the place to delve into the technical details of the laws of vows; the point is that the father forbids his son from deriving any benefit from his property.
Nevertheless, "Yamut - yoreshenu" - upon the father's death, his assets pass to his son according to the regular rules of inheritance, and the vow that he made cannot prevent this at all. The son inherits from him and enjoys the assets as he wishes.
The reason for this: The father used the expression "misheli" - from my things, from my assets. There is a sort of halachic law of nature here: upon the father's death, his heirs inherit his assets immediately, and there is no way to stop this. Because of this, the Sages understand that the intention of the one making the vow was only for as long as the assets were his; from the moment they ceased to be his and became the son's assets, the son is once again permitted to benefit from them.
"Bechayai uvomoti":
If the father wished to forbid his son from benefiting even after his death, he would have had to state explicitly, "Bechayai uvomoti" - in my life and in my death - and this is the next case in the Mishnah. By saying so, the son still inherits the assets, as this cannot be prevented, but he is forbidden from deriving any benefit from them.
The wording of the Mishnah is "Yamut - lo yireshenu" - if he dies, he does not inherit him, and this is not technically accurate: the son does indeed inherit, and halachically he has rights to the assets, but he cannot do anything with them. The Mishnah's intention with "he does not inherit him" is that he is not permitted to benefit from them.
And what should he do with assets from which he is unable to benefit? "Yachazir levanav ule'achav" - he must transfer them to the other legal heirs, just as we saw in the previous Mishnah:
"Levanav" - his father's sons, meaning his brothers and half-brothers.
"Ule'achav" - if there are no other brothers and he is an only son, the assets are transferred to the deceased father's brothers, who are the heirs when a person has no children.
The underlying principle is simple: there is no point in inheriting something from which one cannot benefit.
"Ve'im ein lo":
The words "**Ve'im ein lo**" - And if he does not have, must be understood the same way we understood them in the previous Mishnah: it means nothing other than he lacks the financial means that would allow him to give up the financial benefit of the inheritance. If his wife and children are starving to death, and without the inheritance they will remain hungry, he cannot simply say, "This is what my father said" - and therefore, an avenue of circumvention is opened for him.
Tosafos notes that in the previous Mishnah, two options were stated - "**eino rotzeh**" - he does not want to, or "**ein lo**" - he does not have - whereas here it only says "**ein lo**". This implies that this circumvention is not meant for someone who simply wants to benefit from his father's assets, but only for someone who practically cannot give up the inheritance because he needs it desperately. Only in such a situation is the option of circumvention available to him.
The circumvention: "**Loveh uva'alei hachov ba'in venifra'in**" - He borrows, and the creditors come and collect:
The heir borrows money from a third party using the forbidden assets as collateral, and he does not repay the loan. The creditor comes, forecloses, and collects payment from the collateral against which the loan was given - exactly like in the previous Mishnah.
For example: The father had a luxury car in the driveway, and it was his only asset, and he said to his son: "You will never benefit from my car, it is forbidden to you like a korban during my lifetime and after my death." This is the only thing the son will inherit. The son goes to the bank, borrows money against the car, and now has forty thousand dollars in hand; meanwhile, the bank comes and takes the car for itself.
The main idea: The son does not take ownership of the vehicle and does not hand it over to the bank. Rather, the bank takes it unilaterally, and therefore it is not considered that he received a direct benefit.
The foundation of this concept is found in Tractate Nedarim: Even one who vowed not to provide benefit to his fellow is permitted to pay off his debts, and this is not considered a direct benefit. This halachah is consistent with what we learned in Tractate Nedarim and Tractate Shekalim, and expanding on it is beyond our scope.
In summary: The circumvention before us is that the son borrows money against the asset from which he is forbidden to benefit, and the lender collects the asset for himself. In this way, the son extracts financial benefit without actually possessing the asset and without receiving direct benefit from what was forbidden to him.