When scholars in the last century found a treasure trove of documents while excavating the site of a medieval synagogue in Cairo, they came across something that showed Jews of that time knew how to relax.

It was “a note that someone sent to someone that said, please buy me these textiles and also some hashish,” explained Eddy Portnoy, curator of a new exhibit in New York on Jews and cannabis. “Sort of like a 12th-century Venmo: Please buy me weed.”

A copy of that document is part of the exhibit, titled “Am Yisrael High.” Portnoy, the director of exhibitions at the YIVO Institute for Jewish Research in Manhattan, will discuss the exhibit and the long, rich history of Jewish involvement with cannabis on May 15 in a lecture at Berkeley’s Congregation Beth El organized by New Lehrhaus.

Portnoy said the Cairo letter is only one of the many pieces of evidence that prove the longstanding connection between Jews and the psychoactive plant — from indications of early ritual use; to Jewish activism in the legalization fights of recent decades; to pioneering Israeli research in medical marijuana; to the disproportionately high number of Jews in the cannabis industry today.

“It’s really fascinating,” he said. “There are aspects to this that a lot of people don’t know about. It’s fascinating historically and culturally.”

The exhibit, which opens May 5 at the YIVO Institute, features not only historical documents but also modern objects, including the Jewishly branded kosher cannabis products sold by Carmel Valley-based Mazel Tov Farms, which is a co-sponsor of the event.

“I’m really honored and excited,” said Melissa Whitley, who owns Mazel Tov Farms with her husband, Cary Neiman. The company donated products and a “modest” sum to the exhibit, according to Neiman. He said the company’s participation wasn’t about marketing the brand, but out of appreciation at being part of YIVO, the only prewar European Jewish archive and library to have survived the Holocaust.

“To me, it’s more a recognition of the unique space where Jews and cannabis intersect,” he said.

The exhibit also includes objects that reference religion, including Mazel Tov Farms-branded kippahs and two different cannabis-based haggadahs for Passover. (Medicinal marijuana use has been deemed kosher for Passover by rabbinic authorities.)

Today, there are plenty of examples of Jews incorporating marijuana into religious rituals. Portnoy said it’s not new — the practice has a long history.

In the 1960s, an archaeological dig near the Dead Sea excavated an eighth-century set of altars with remains of burned incense, which a lab found to be from frankincense and cannabis. There’s even speculation that the “aromatic cane” referred to in the Torah (קנה בשם, or kaneh bosm) was cannabis.

“The people who are bringing it back are actually engaging in something that existed previously,” he said.

Jews over time have also acknowledged that cannabis use is fun: One feature of the exhibit is a poem by Nasir, a celebrated Jewish entertainer in Cairo around the start of the 14th century. Like the note asking for hashish, Nasir’s poem was one of the documents found in the Cairo Geniza, or book storage area, where damaged prayerbooks or Torahs were kept before burial. The Cairo Geniza was also a place to get rid of a host of nonreligious documents, making it a valuable and fascinating resource for scholars of medieval Egypt.

Nasir’s poem sets up a rivalry between those who love wine and those who love hashish — he comes down strongly on the wine side, belittling confused stoners who prefer hashish.

“Hashish has a way of scrambling the brain/You aim for Qalyub, and you land in Banha. That dude over there, stoned out of his mind/He’s like a ghoul, eating all in his path,” the poem begins (in a translation by Alan Elbaum).

“This is something people still say about people that get high!” Portnoy said, referring to “the munchies.”

In addition to the lecture on May 15, Portnoy will talk about some of the same topics on May 5, when the YIVO exhibit opens. He’ll be moderating a panel (also available to watch virtually) with guests that include the Bay Area’s local guru of marijuana cultivation, Ed Rosenthal. Rosenthal is a Piedmont-based author of many books about cannabis, including one that’s considered the bible of home growing.

Portnoy first got interested in the idea of an exhibit about Jews and pot when he came across the now-infamous menorah bong (it “might not be great at holding candles, but it will definitely inspire its users to consume plenty of latkes,” one reporter wrote of the device in 2015).

YIVO’s archivists gather objects that reflect Jewish material culture, preserving evidence of how Jews live by collecting the items that Jewish people use and create. It may not be obvious at first that a menorah bong should join the archive, Portnoy said. But the bong, too, is a part of living Jewish history.

“I felt to myself this menorah bong is really an unusual part of that,” Portnoy said. “It should really belong in our archives.”