Who inherits if a man and wife die together?

Question

Bava Batra 158a talks in the mishna about the case where a man and his wife (with no children) die together. The heirs of the man claim that the woman died first so they inherit everything, while the heirs of the wife claim that the man died first so they inherit. Beit Shammai says they divide the estate, while Beit Hillel says that the wife's heirs inherit what was hers (e.g. dowry) and the man's heirs inherit what was his.

I've been taught that Beit Hillel almost always wins these disputes. In the g'mara here (158b), Reish Lakish in the name of Bar Kappara says they divide -- he seems to be supporting Beit Shammai. Nobody here says otherwise. The daf then goes on to the next mishna. which talks about a related case (a man and his mother die together). This made me wonder how the question is ultimately resolved.

What is the halacha (assuming there have been no specific directives)? Do they divide the estate per Shammai or do they resolve each part of the estate per Hillel? The Jewish Encyclopedia article on inheritance doesn't talk about this special case, nor does this set of Q&A about inheritance law that I found. Those were the most-promising results I found in searching. I don't yet know how to navigate Shulchan Aruch (where I would expect to find something).

This is not a practical matter for me; I'm just curious after I came across this passage and tried unsuccessfully to follow it to an answer.

Answer 1

Your friend here is the commentary called "עין משפט נר מצוה -- Ein Mishpat Ner Mitzva" located in the upper corner of any standard Talmud page that has a legal ruling on it which is brought by either Maimonides or the Shulchan Arukh. It should be right next to the page number. The mark in the text which references to it is a superscript non-rashi-script Hebrew letter right in the Gemara before the text being ruled like, starting with א for the first ruling on each page. In your case, we see the little א next to Beit Hillel's comment on 158a and next to Bar Kapara's comment on 158b. This is a strong indication that the Halakha is like them.

Following up to the corner, we look at the note next to the א which was being referenced. On 158a we find:

מיי׳ פ״ה מהל׳ נחלות הל׳ ו סמג עשין צו טוש"ע אה״ע סי׳ צ סעיף ו‏

This looks cryptic, but if you remember a few abbreviations you can find what you need, and it helps that the format of these notes is very consistent as you'll quickly notice. מיי is short for מיימון AKA Maimonides. סמג is Sefer Mitzvot Gadol. טוש״ע is short for טור שלחן ערוך ie. the Tur and Shulchan Arukh which use similar sectioning.

Knowing this, the above comment becomes:

מיימון פרק ה הלכות נחלות הלכה ו. ספר מצות גדול עשה צו. טור שלחן ערוך אבן העזר סימן צ סעיף ו
Maimonides Laws of Inheritance 5:6. Sefer Mitzvot Gadol positive command #96. Tur/ShA Even HaEzer 90:6.

And those are the places you can find that ruling of Beit Hillel's recorded. (Try yourself now understanding the note on 158b. It should be very similar since these are very related laws.)

Here's Maimonides' ruling there:

מי שנפל הבית עליו ועל אשתו, ואין ידוע אם האישה מתה תחילה, ונמצאו יורשי הבעל יורשין כל נכסיה, או הבעל מת תחילה, ונמצאו יורשי האישה יורשין כל נכסיה--כיצד דינם: מעמידין נכסי מלוג בחזקת יורשי האישה, והכתובה עיקר ותוספת בחזקת יורשי הבעל; וחולקין בנכסי צאן ברזל, יורשי האישה נוטלין חציין ויורשי הבעל חציין.‏
The following rules apply when a house fell on a person and his wife and they both died. It is not known if the woman died first, in which instance the heirs of her husband inherit her entire estate, or the husband died first, and the woman's heirs inherit her estate.

How is the issue resolved? We consider the nichsei m'log to be in the possession of the woman's heirs. The money due her by virtue of her ketubah - both the essential obligation and the additional amount - are considered to be in the possession of her husband's heirs. Her nichsei tzon barzel are divided, half are given to the woman's heirs and half to the husband's heirs.

It seems (and you can see this in Rashbam's commentary on the Mishna) that the discussion in the Gemara was about whose Chazaka the Nikhsei Tzon Barzel are in, and the conclusion is a doubt so we split. But in principle we agree with Beit Hillel so for the Nikhsei Milog and the Ketubba which have a clear Muchzak, they win. (Of course there could be other ways other Rishonim understand the Mishna and Gemara, but this seems to resolve your confusion.)