When Rabbi Eliezer Finkelman starts a discussion on cross-dressing, he isn't about to bring up the benefits of smudge-free mascara or low-heeled pumps.
Instead, he pulls out ancient Jewish texts to get to the heart of Deuteronomy 22:5, commonly translated as: "A woman shall not wear that which pertains to a man, neither shall a man put on a woman's garment: for all that do so are abomination to the Lord your God."
"As usual when you have a written text, it cries out for interpretation," said Finkelman, the spiritual leader of Berkeley's modern Orthodox Congregation Beth Israel.
Finkelman is in the midst of teaching a six-week course advertised as an exploration of Jewish law on cross-dressing.
The class, which meets at 8 p.m. Sundays through mid-December, isn't a series of lectures on what traditional Judaism allows men and women to wear. Instead, it traces interpretations of the biblical verse from ancient to modern days.
If people are looking for an absolutist interpretation of this prohibition, they're attending the wrong synagogue.
"The history of Jewish law is the history of difference of opinion," Finkelman said.
Some sources eventually decide that cross-dressing is prohibited in all instances, even on Purim when men customarily dress up like women; others say it's prohibited only when the intention is to create illicit sexual opportunity through deception.
Today, Finkelman said, "certainly a drag queen is violating this prohibition."
But the 20th-century Orthodox community is split on the commandment's subtler undertones.
The ultrareligious community, for example, will say the verse means that women may wear only dresses and skirts, Finkelman said, while the centrist or modern Orthodox community will say that women may wear pants as long they're "not cut to be provocative."
Within even the ultrareligious community, Finkelman added, some rabbis would say that women can wear pants when they're appropriate to the activity at hand — such as skiing or horseback riding.
The legal tradition is also "sensitive to fashion," Finkelman said. Two centuries ago in Turkey, he said, women who didn't wear the baggy pants of the day would have been considered "bizarre."
And a few years back, American men who wore earrings attracted a lot of attention because they were thought to be making statements about their sexual orientation.
"Now it is boring," Finkelman said.
On the first night of the class earlier this month, a dozen men and women gathered around a table in Beth Israel's sanctuary.
They spent 90 minutes discussing Jewish law and listening to the rabbi read from the earliest sources on the verse.
Ancient translations of the Hebrew text into Aramaic, in fact, offered widely varying interpretations of the verse, Finkelman told the class.
One of the texts, known as Targum Unkulus, which Finkelman called "possibly the oldest authoritative translation," was prepared around 100 to 200 C.E. It translates the verse into a prohibition against women carrying weapons and against men using the "vessels" of a woman.
According to this source, Finkelman said, a woman would be allowed to sport a tuxedo, bowler hat and cigar, but she would break the law "as soon as she puts on her Uzi."
Another of the Aramaic texts, Targum Yonatan ben Uziel, which was written around the same time as Targum Unkulus, translates the verse into a ban on women wearing tzitzit or tefillin and on men trimming their groin or underarm hair.
But those texts weren't the final word on the Jewish dress code, said Finkelman at the end of the first class. "We'll see how this marches down the history of Jewish law."
Elza Behrens, a Beth Israel member attending the class, said she was relieved to see how Finkelman approached the topic.
When the class was announced, she said, congregants had "huge reactions" to it. Some women, especially feminists, were concerned about being confronted with a prohibition against wearing pants. Others worried about the direct implications for homosexuals.
"We all have assumptions about what this thing says," Behrens said. "People assume there's this stuff they don't want to know."
But studying the ancient texts helps allay such concerns for Behrens.
"It turns a lot of this on its head in a good way," she said. "It proves the point over and over that [Jewish law] gives us a lot of room about how to live our lives."
The class originated in a general lecture Finkelman gave earlier this fall on the classic texts of Jewish tradition. Congregants asked for a follow-up class that would track a single topic through all of the texts.
Finkelman picked cross-dressing because it was a specific and "fun" topic, although he added that "for people who have a strong desire to cross-dress, this could not be a funny issue at all."
The rabbi said he planned to present the subject in a "straightforward" but "sensitive" manner.
"I don't have to be afraid of being who I am," he said, "or teaching the Jewish tradition as I understand it."