[Avodah] gezerot of Sanhedrin

[Eli Turkel]

<<(I think you mean Rava, as it's called gezeira deRava.) >>

The gemara in RH 29 on the Mishna that in the days of the
Temple when RH fell on shabbat the shofar was blown only
in the Temple (or all Jerusalem)

The first opinion in the gemara is that this is a Torah law (like
the Yerushalmi I quote). Rava disagrees and says it cant be a Torah
law. Rather he explains it based on the principle of Rabbah that
they were afraid that people would take the shofar to public areas
to learn how to blow it. The gemara then extends the explanation
to megilla and lulav.

As previously explained the Yerushalmi accepts that it is a Torah prohibition,
explains that megilla is not read on shabbat because it is ketuvin and doesnt
discuss lulav.

The simple pshat in the gemara is that indeed this was a gezerah of the
Sanhedrin in Temple days and ava is only explaining it based on the
reasoning of Rabbah.

As to whether one needs a sanhedrin for gezerot that is very controversial
and goes back to the controversy on why halachot in the Gemara and Mishna
are binding. Rambam seems to explain that simply it was accepted by
all of Israel.
Hence gezerot after that time are less binding though many gezerot of the
geonim were accepted. Rabbenu Gershon who lived later had less power.
As I point out in an article of mine the cherem of Rabbenu Gershon is in
fact not his private psak but rather by the central bet din of the German
community most probably at some community meeting. Similar remarks apply
to Cherem's of Rabbenu Tam. Hence, these do not affect sefardim who
were no part of that community

We have many gezerot in the Mishna based on some Tanna's opinion.
There is no indication that each case was voted by the Sanhedrin of its time.

BTW I am not completely convinced of the difference between a prohibition and
a cherem. Certainly the cherem is binding whether one wants to or not and
would be enforced by a bet din.


Eli Turkel