[Avodah] halachic derivation rules

[Micha Berger]

On Fri, Apr 14, 2023 at 04:29:01PM +0300, Joel Rich via Avodah wrote:
> These seem to come in a number of different flavors such as a possible
> extra letter (e.g. megillah 17b dvarim/hadvarim) or an extra word (eg bava
> metzia 27b mimenu).

This is ribui umi'ut, R Aqiva style derashah.

There are two schools of derashah: DeVei R' Aqiva and DeVei R Yishma'el.
And each wrote their own midrashei halakhah. More detail at
https://aspaqlaria.aishdas.org/2021/08/03/midrashei-halakhah-2

Rabbi Yishma'el's 13 rules are all about what phrases mean. He is the
one who says "dibera Torah belashon benei adam". Kelal uperat is about
whether a given text means something inclusive or more limited.

Meanwhile, R Aqiva's list of 19 rules are more about keywords -- "akh"
and "raq" are mi'utim. Even "es" became a ribui.

The double use of the shoresh in "aseir te'aseir" means something to
R Aqiva's school, whereas it's just how Hebrew works to R Yishma'el.

It's R Aqiva's school that produces mishnah -- R Aqiva, R Meir ("stam
mishnah keR Meir), to Rebbe. So although we talk about R Yishma'el's
rules in shacharis, it's R Aqiva's that end up having greater weight
in halakhah.

Also, with regard to gezeira shava, some held as long as the word is
noteworthy in one usage, there were grounds for a GS. Others required
it be derashah-worthy on both sides. Shemu'el didn't require anything
beyond common usage (i.e. even when the GS is einah mufnah kol iqar).
https://he.wikipedia.org/wiki/%D7%9E%D7%95%D7%A4%D7%A0%D7%94

In any case, it therefore often happens that their are derashos that
one tanna uses that doesn't exist for and therefore doesn't need to be
reused by his bar pelugta.

Tir'u baTov!
-Micha

-- 
Micha Berger                 The thought of happiness that comes from outside
http://www.aishdas.org/asp   the person, brings him sadness. But realizing
Author: Widen Your Tent      the value of one's will and the freedom brought
- https://amzn.to/2JRxnDF    by uplifting its, brings great joy. - R' Kook