Bava Basra, Chapter 9, Mishnah 8. This Mishnah, along with the following two Mishnayos that conclude the chapter, deals with situations where the laws of inheritance are applied, but it is not known which of the two involved parties died first - and the order of deaths will determine how the inheritance is divided.
The case before us:
Reuven and his father were in a house together, the house collapsed on them, and they both died, and it is unknown who died first. Reuven was completely destitute at the time of his death, whereas his father was a wealthy man. Reuven owed the payment of a kesubah to his wife, or a debt to another creditor, and the father had other sons who stood to inherit him.
A special condition in the contract:
Strictly speaking, the lien of a kesubah applies only to properties that were in the husband's possession at the time of the marriage. However, a person can explicitly stipulate that even properties that will come into his possession later - land that he purchases or money that he acquires - will also be subject to a lien for the payment of the kesubah. This exceptional condition was established in the case before us, both in the kesubah and in the promissory note.
The claims of the parties:
The father's heirs: Reuven's brothers claim that Reuven died first and was out of the picture, and therefore the money passes from the father directly to them.
The wife and creditors: They claim that perhaps the father died first, and then Reuven inherited his share, and that inheritance became subject to the lien of their contracts - and by virtue of this they come to collect what is owed to them.
The text of the Mishnah:
"Nafal habayis alav ve'al aviv" - The house collapsed and killed both of them, Reuven and his father.
"O alav ve'al morishav" - There is no practical difference whether the second person was specifically his father or another benefactor, such as his uncle or his grandfather, from whom Reuven was destined to inherit property. The law is the same.
"Vehaysah alav kesubas ishah uva'al chov" - Reuven bears the obligation of paying a kesubah to his wife, which stands to be paid upon his death, or alternatively a debt to another creditor - and at the time of the kesubah or the loan he committed that their lien would apply even to properties that would come into his possession in the future.
"Yorshei ha'av omrim: haben mes rishon ve'achar kach mes ha'av" - And therefore we are the only heirs who existed at the time of the father's death, and Reuven's wife and his creditors have no share in the matter.
"Uva'alei hachov omrim: ha'av mes rishon ve'achar kach mes haben" - And at that moment Reuven inherited his share, and died possessing liened properties - and from them our debt must be paid in full.
And they disagree on the matter: "Beis Shammai omrim: yachloku, uVeis Hillel omrim: nechasim bechezkasan" - Beis Shammai say they divide it, and Beis Hillel say the property remains in its presumed status.
The starting point - the logic of chazakah:
Seemingly, the law should be as follows: It is known with certainty that the money belonged to the father, and it is known with certainty that his remaining sons are his heirs. Therefore, the presumptive status (chazakah) is in their hands, and anyone coming to challenge them must bring proof. A mere doubt, whether the order of deaths was in favor of the claimants or not, is insufficient. It emerges that the creditor or the wife are the ones attempting to extract property, and the burden of proof rests on them; and since they have no proof, the money remains in the place where we know with certainty it is situated - in the father's estate - and from there it passes directly to the remaining sons. This is the opinion of Beis Hillel.
The Opinion of Beis Shammai:
Beis Shammai have a unique principle: a document in a person's hand, since he has the power to collect with it, is halachically considered as if he has already actually collected it - and the holder of the document is thus in possession. Therefore, even though the brothers are certain to inherit, the wife and the creditors also hold a document and are considered in possession, and the status of both sides is equal.
For if the father died first, Reuven would inherit, and the document holders would collect first and take their full debt - the wife would take the two hundred zuz of her kesubah; whereas if Reuven died first, she takes nothing. And since in the one scenario she is considered in possession equally with the brothers, Beis Shammai say: they divide it.
If there are more than two hundred zuz in the estate - the wife takes one hundred zuz, half of her kesubah.
If there are less than two hundred zuz in the estate - they divide whatever is available between them, since her status is no worse than theirs.
The Opinion of Beis Hillel and the Halachah:
Beis Hillel disagree and establish that holding a document does not render its owner in possession. The ones certainly in possession here are the surviving brothers, since they are definite heirs taking from the one who was certainly the last known owner - the father. And this is the halachah: the sons take everything, and the wife and the creditors take nothing, unless they bring proof that the father died first - something they are unable to do.
In summary: In this Mishnah we discussed a case where a house fell on a person and on his bequeather and it is unknown who died first, when there is a kesubah or debt resting on the son whose lien was extended even to future assets. The father's heirs claim that the son died first, and the creditors claim that the father died first. Beis Shammai hold that a document makes its owner in possession, and therefore they divide it; while Beis Hillel hold that the presumption of ownership remains with the definite heirs, and the assets remain in their presumed status - and this is the halachah.
In the next two Mishnayos, which conclude the chapter, we will continue to discuss similar uncertainties in the laws of inheritance.