[Avodah] Halachic justification for short sleeves

[Moshe Feldman]

Rabbi Yehudah Herzl Henkin has good Tradition article on this: "Contemporary
Tseni'ut" --found at
http://www.traditiononline.org/news/article.cfm?id=100680.

In Section A, he has a comprehensive discussion on what part of the zero'a
needs to be covered and concludes:
<< A typology can be established, then, as follows:

1. sleeveless dresses-forbidden by all opinions, as body can be seen.
2. short sleeves, loose-forbidden by all opinions if body can be seen.
3. short sleeves, tight-body cannot be seen, but forbidden if most of the
upper arm is uncovered (rubo ke-kulo)

4.sleeves half-way to elbow-forbidden because of tefah meguleh, room for
limmud zekhut 
5. sleeves to within a tefah of the elbow-minimum permitted
6. sleeves to elbow-recommended
7. sleeves to below elbow-first level humra
8. sleeves to wrists-second level humra.
>>

He also notes that covering the arm is based on Das Yehudis:
<< Zero'oteha megulot is the same regarding Keri'at Shema as it is regarding
Dat Yehudit, the binding customs of modest Jewish women.

In Ketubot 72b, "R. Yehuda said that Shemuel said, '[Dat Yehudit is
violated] if she displays her upper arms to people.'"
>>

In Section B of the article, he discusses whether Das Yehudis is fixed
(l'kulah) as of the time of the gemara, or whether it depends on the custom
of the particular locale (even l'kulah): 
<< Rashi76 defined Dat Yehudit as practices adopted by Jewish women
(shenahagu benot Yisrael) that are not required by Scripture. A number of
Rishonim imply that these practices vary according to time and place.
Tosafot Rid77 writes that Dat Yehudit does not inherently involve a
prohibition, but only that "women behave [nohagot] in such fashion as a way
of tseni'ut," in the present tense, i.e., it depends on contemporary
practice. Semag78 writes that Dat Yehudit requires that a woman wear a shawl
"like all the other women" (ke-shaar kol ha-nashim); hence, if the others do
not wear one, neither need she.

Moreover, Rambam is clear79 that Dat Yehudit varies from place to place. For
what he says in Hilkhot Ishut 24:12: . . . .
>>

RYHH does not specifically state that his "typology" of zero'a covering in
Section A depends on the practices of the locale, and that in a locale where
women wear short-sleeves (even less than half-way to the elbow), this is
permitted.  However, this would seem implied by his discussion in Section B.
Unfortunately, he did not integrate Section A and Section B.

Kol tuv,
Moshe