Is a public conversation between two rabbis in their late 70s a hard sell for a summer evening out? Not in Jerusalem. Tickets for the July 2 event at the Dan Panorama Hotel were gone before you could say Jacob Robinson.

It was a rare reunion for the rabbis, like that of their contemporaries Simon and Garfunkel. My husband and I were there in 2004 when the singing duo drew an audience of 600,000 for a gig in Rome at the Coliseum. The number had us thinking about an eruv, a designated space considered a private domain according to Jewish law. It was the type of issue we learned to contemplate from tonight's two speakers: Rabbi Chaim Brovender and Rabbi Shlomo Riskin.

When moderator Rabbi Jeffrey Saks, the head of ATID-Academy for Torah Initiatives and Directions, asks how many in the audience had studied with either or both of the rabbis, nearly every hand flies up. Over the last five decades, these two immigrants to Israel from the United States have revolutionized Torah study in Israel and the Diaspora.

"I'm not a maverick, I'm just a nuisance," says Brovender with his characteristic self-deprecating humor.

While some in the crowd grew up in religious homes in the US, like Brovender did, the majority, like Riskin, did not. Many who are today knowledgeable, observant Jews came to Torah study well-schooled in Aristotle and Einstein but, as they say, didn't know Abram from Adam.

Both had a hard time getting a job when they moved to Israel.

Rabbis Brovender and Riskin have a lot more in common than that. Both were born in Brooklyn. Both graduated from Yeshiva University. Both have doctoral degrees in addition to Orthodox rabbinical ordination. Brovender, a math major, knows extinct Semitic languages such as Akkadian. Riskin reads classical Greek. They both received ordination from Rabbi Yosef Dov HaLevi Soloveitchik. While neither is a hassid, both were influenced by the Lubavitcher rebbe. Both have pioneered innovative Torah institutions; and they're both Zionists.

BROVENDER, WHO was once abducted and injured by Palestinians, begins the evening by declaring that our relationship with Arabs is our most challenging responsibility as Jews. Rabbi Riskin worked with a mukhtar (Arab village head) to provide health services for the nearby village, but was also arrested for protesting the Oslo process.

Still, there's tension in the air as the two are escorted onto the stage. As with Simon and Garfunkel, not all has been harmonious. There have been bridges over troubled waters.

Rabbi Chaim and Miriam Brovender were activists in the Bnei Akiva youth movement and made aliyah in 1965, Rabbi Brovender's first trip to Israel. He was under the impression they were headed to Kibbutz Lavi near Tiberias, not knowing that Miriam canceled the farm pick-up. Instead, they settled in a single room in a Jerusalem absorption center and have lived in the capital, where they have brought up six children, ever since.

He bought a motor scooter, served in the IDF and delivered mail during the Six Day War. A friend then encouraged him to engage in intense Torah study at the newly established Lithuanian-style Itri Yeshiva. It was there that Brovender became enthralled with the passionate Talmudic learning he would later specialize in passing on to others.

"I understood that a Jew could define himself or herself through the books the Jews had produced. That was a compelling idea." On a trip back to the US, the Lubavitcher Rebbe told Brovender that he needed to teach Torah. Itri Yeshiva founder Rabbi Mordechai Elefant asked Brovender to start a program for beginners: Diaspora Jews without a text-based Jewish education. The yeshiva was first called Hartman's and then Shappell's. Eventually, Brovender started Yeshivat Hamivtar. By then, someone had already slashed the tires on Brovender's car for teaching Talmud to women. As he admits, the "logistics" needed to run a school were not his forte.

Brovender was eventually rescued by Riskin, who indefatigably traveled the world to raise funds for the network of institutions that would become Ohr Torah Stone, and made Yeshivat Hamivtar part of OTS.

RISKIN'S FIRST Torah teacher was his devout and learned grandmother. While still a young rabbi, he was labeled "Stevie Wonder" by the media for founding Manhattan's famed Lincoln Square Synagogue, an Orthodox institution that featured a serious and engaging educational program along with Shabbat services for beginners. He and his wife, Victoria Pollins Riskin, moved to the new no-frills city of Efrat with their four children in 1983, encouraging their congregants to follow. Most didn't.

Said Riskin, "In America I'd founded two yeshivas. So I was sure that if I could be the rabbi of any synagogue of my choice in America, I would have no problem finding my niche in Israel. But it was hard. They wouldn't even let me give a model lesson."

The problem? No beard. Friend Moshe Moskovics, who chaired the Judean Hills Development Company, advised the boyish-looking rabbi that the way to get a job was to build a city. Moskovics became mayor of Efrat and Riskin became the city's rabbi. Riskin challenged the Israeli educational system with new ideas. He built residential high schools that integrated excellent general education with Torah studies. He started rabbinical colleges and Torah academies for men and women – 27 institutions in all. He stood up to the Chief Rabbinate when it refused to grant city rabbis the authority to convert non-Jews according to their halachic understanding.

Tonight, the moderator, wanting to create a little controversy, asks Rabbi Riskin if he predicts Orthodox women will be rabbis in the next 20 years. He points out that morot hora'a – women who can make rulings on Jewish law – are already graduating from his institutions. Rabbi Brovender adds his belief that women's Torah learning has done the opposite of causing a rift. "My intuitive feeling is that in the more right-wing schools and systems the respect for women as students is going up."

Those who have come hoping to see sparks fly are disappointed. Both rabbis remain erudite and charming as they reminisce and prognosticate. The differences between them seem more about issues of nuance than substance. Unlike the words of Simon and Garfunkel's sages, the words of these men's prophets are written in the sacred books, not on the subway walls. They've listened to Jeremiah, who said when times are tough, build a house in Israel

Rabbi Brovender received a Sylvan Adams Nefesh b'Nefesh award in 2017. Rabbi Riskin is among this year's award recipients. The prize is called Bonei Zion, Builders of Zion. May they keep on creating and building.