[Avodah] How does Prozbul work?

[Micha Berger via Avodah]

On Wed, Sep 16, 2015 at 03:08:53PM +0300, Eli Turkel via Avodah wrote:
: I have no idea how R Melamed got his numbers. RAL seemed to hold that
: once a few generations have passed that a family has no connection with
: yiddishkeit then the family would no longer be halachically Jewish even
: for direct maternal descendants.

This was his famous teshuvah on the Brother Daniel case. That there
are limits even on maternal descent.

I found a nice summary by R/Dr Judah Goldberg
<http://www.etzion.org.il/en/shiur-15-jewish-peoplehood-8-leaving-judaism>

: i.e. if someone could prove they were a descendant of shevet ephraim
: through a direct maternal link the person still would not be Jewish.

>From there, RAL's meqoros in shas:

    In Yevamot 16b, Rav Assi states that if a gentile betroths a Jewess,
    we cannot dismiss the validity of the marriage, for perhaps he
    descends from one of the ten lost tribes. When Shmuel heard this
    ruling, however, he responded, "They did not move from that place
    until they made [the descendants of the lost tribes] into absolute
    gentiles, as it says, 'They have betrayed God, for they have begotten
    alien children' (Hoshea 5:7)" (17a). Similarly, Chullin 6a tells how
    Rav Ami and Rav Assi discovered that the Samaritan community, which
    had long been suspected of engaging in pagan worship, was no longer
    observing Jewish law at all. In response, They did not move from
    that place until they made [the Samaritans] into absolute gentiles.

He cites three shitos from rishonim, although the Rambam's pesaq is as
explacated by R' Chaim Brisker.

1- Rashba: The Samaritan's conversion was annulled, not that one can
   stop being a Jew. R Pinchas Horowitz (Sefer Ha-mikna) applies parallel
   reasoning to the 10 shevatim -- they didn't stop being Jews, they
   are just an ignorable mi'ut that only a derabbanan kept us from ignoring.
   And that was repealed.

2- A mi'ut hold that the geir who stops believing ceases being a geir,
   but we have to worry about what's really going on in his head, so
   lechumerah we have to acknowledge his marriage.

3- The Rambam as explained by RCB (contrasting Ishus 4:15 with peirush on
   Niddah 7:4, where he says a dead Samaritan is not metamei tum'as ohel)
   that someone who gives up his self-identity as a Jew and acts on it
   is

But in either case, the hypothetical Ephramite is a machloqes amoraim.
Unless you agree with the author of the Hafla'ah that it's just an issue
of mi'ut, and therefore the one who could prove he is in the mi'ut would
be Jewish.

GCT!
-Micha

-- 
Micha Berger             In the days of our sages, man didn't sin unless
micha at aishdas.org        he was overcome with a spirit of foolishness.
http://www.aishdas.org   Today, we don't do a mitzvah unless we receive
Fax: (270) 514-1507      a spirit of purity.      - Rav Yisrael Salanter