[Avodah] lulav on shabbat

[Zev Sero]

Eli Turkel wrote:

> 3. EY keeps one day yomtov while Bavel keeps 2 days
> from the above daf yomi in the name of the Lechem Mishneh
> "The Rabanan do not institute an active practice, a "Kum v'Aseh," such
> as the requirement for the Jews in Eretz Yisrael to observe a second
> day of Yom Tov"
> However, this is exactly the later takanah when there was no longer a
> safek that Jews outside EY do keep 2 days. So they did institute a
> "kum aseh" when they wanted to.

That wasn't an order to start doing something, it was an order not to
stop something they were already doing.  This explains why it applied
only to those places that were already keeping the 2nd day, even though
the reason given (that government decrees may suppress central halachic
authorities, leaving the calculation up to each individual, and people
may miscalculate) was actually stronger at that time in EY than it was
in Bavel.  It also explains why only 2 days are required, and not 3 in
case someone's miscalculation added a day instead of subtracting one.
These worries were not enough to justify imposing a change in existing
practise, but they were enough to justify forbidding such a change.

-- 
Zev Sero                      The trouble with socialism is that you
zev at sero.name                 eventually run out of other people’s money
                                                     - Margaret Thatcher