The crowd was eclectic, from stern, black-garbed ultra-Orthodox men to youths of both sexes bedecked in colorful, hippie-like clothes. They hailed from homes as far as Safed, the kabbalist center in Israel’s North, and as remote as isolated hilltop settlements in the occupied West Bank. Even a few New Age types from secular Tel Aviv were in evidence.

The 3,000 men, women and children at Tel Aviv’s newly renovated Habima Square last December were waiting anxiously to hear Rabbi Yitzchak Ginsburgh, the St. Louis-born mystic and scholar whose quiet demeanor belies incendiary scholarly writings that are inspiring a generation of Jewish supremacists.

The venue marked something of a mainstream coming-out milestone for Ginsburgh. Every year since 2011, in cooperation with the Chabad Hasidic sect, Ginsburgh has held an epic event on “Redemption Holiday,” a Chabad-Lubavitch festivity set for the 19th of Kislev on the Hebrew calendar — the day in 1798 that czarist authorities in Russia released Chabad’s founder, Rabbi Schneur Zalman, from jail. After years of staging the event in heavily Orthodox Jerusalem, this was the first time that Ginsburgh, a longtime Chabad adherent, held the event in Tel Aviv, in one of the city’s most prominent secular venues.

An American transplant to Israel, Ginsburgh is best known for his teachings that seem to give license to Jewish vengeance attacks against Palestinians. His critics claim that Ginsburgh’s influence lies behind the worst Jewish terror attacks of the past 20 years, from the assassination of Prime Minister Yitzhak Rabin, to the massacre in Hebron of 29 Palestinians by Baruch Goldstein, who he hailed and endorsed in a book soon after the murders.

But Ginsburgh’s followers view him as no less than a prophet.

“Secular Zionism is stagnant and has nothing left to offer. Even Bibi [Prime Minister Benjamin Netanyahu] does not know how to cope with terror,” said Tzviki Basok, a 29-year-old resident of the tiny West Bank settlement of Ahaia who identified himself as a devoted Ginsburgh follower. A father of six, Basok wore a dark-brown flat cap on his head, slim glasses on his nose, and a perpetually friendly smile that his shaggy beard could not quite hide. “Ginsburgh,” he said, is the “only one who is willing to take responsibility over the entirety of the Jewish nation, according to Torah.”

Ginsburgh’s students include the so-called Hilltop Youth — gaggles of Jewish teens who roam the West Bank hilltops and intimidate Palestinians through acts of vandalism, arson and even murder.

Just a few weeks prior to Ginsburgh’s Tel Aviv event, two of these youths, now under indictment, allegedly firebombed the home of a family in the West Bank Palestinian village of Duma. Two young parents and their 18-month infant burned to death. On the walls of the Dawabsheh family’s home, the arsonists daubed the graffiti messages “Revenge” and “Long Live King Messiah.”

Ginsburgh has a proposal for addressing such outbreaks. In a 2014 public letter to 100 rabbis, he declared that the only way to stop Jewish terror actions, which he referred to as “uncontrolled reactions of youngsters who care about Israel,” is for the government and army to internalize that “the entirety of the State of Israel (including what is called ‘occupied territories’) belongs solely to the Nation of Israel, that it’s every Jew’s right to settle anywhere he pleases, and that the role of the army is only to protect Jews.”

At 71 years old, Ginsburgh still stands tall and confident in a Hasidic black coat and hat. But the rabbi’s most defining physical feature is his snow-white beard, which reaches midway down his chest. In a myth often repeated by his students, Ginsburgh’s beard is said to have turned white the night that he was attacked by Arab stone throwers on a hike in 1998 that left him otherwise unharmed. Since then, he has been known as “The Angel.” It’s been a long journey for him, from a secular upbringing in St. Louis to his role today as a Kabbalistic guru to a generation of highly radicalized, violence-prone West Bank young people. Today, his reach into Israeli society runs deep.

Ginsburgh is the spiritual leader of the Od Yosef Chai (“Joseph Still Lives”) yeshiva — a West Bank seminary that has produced successive cohorts of radical students implicated in violence against Palestinians—and the clerical eminence behind a wide network of villages, neighborhoods, elementary schools, yeshivas, publishing houses. He directs a youth movement, a news website, a center for Jewish psychology and even a political movement, called Derech Chaim, of about 4,500 activists who support the idea that “the essence of the Jewish State is to become the Kingdom of Israel,” according to the movement’s official website. One of Derech Chaim’s major projects is the Hebrew Labor campaign, a title that whitewashes the real purpose of the project: to convince Jewish business owners not to hire Arab workers.

For more than 20 years, many of Ginsburgh’s institutions were supported by the State of Israel through the Ministry of Education, the Ministry of Religious Affairs and the Ministry of Welfare, receiving millions of shekels. Od Yosef Chai’s published financial records, for instance, record budgetary allocations from the Ministry of Education totaling over $221,000 in 2007, a little more than $265,000 in 2008 and almost $293,000 in 2010.

In 2011 the flow of cash from the state to most of his organizations was stopped after the Ministry of Education accepted a Shin Bet assessment that “leading teachers” at Od Yosef Chai Yeshiva foster violence by their students against the Israel Defense Forces and the Palestinians. Published records show that the Ministry of Education still funds two of Ginsburg’s elementary schools in Jerusalem, Torat HaYim and Ye’elat Chen, and that the Ministry of Welfare supports a side project of Od Yosef Chai yeshiva in the Galilee.

A spokesperson for the Ministry of Religion and the Chief Rabbinate told the Forward that the ministry does not allocate funds to Ginsburg’s yeshivas but it does consider graduates of those yeshivas as eligible candidates to become state-approved rabbis.

Private donors also handsomely support Ginsburgh’s organizations through tax-exempt American and Israeli not-for-profits. As reported by Haaretz journalist Uri Blau, the Central Fund of Israel, headed by the New York-based Marcus family, has given Ginsburgh $100,000–$160,000 annually for several years now; the yeshiva’s official’s website still suggests that donations in the United States should be made to the Central Fund of Israel, c/o Marcus Brothers Textile, 980 6th Ave. NYC. Od Yosef Chai’s financial reports show that Keren Hayesod, an Israeli arm of the Jewish Agency, made a one-time contribution of $117,000 to the yeshiva in 2013.

Ginsburgh also runs his own separate not-for-profit educational outlet, the Gal Einai institute — which works closely with his publishing house of the same name — to fundraise in the United States, although most of his donations, public records show, come from private Israeli donors and small businesses such as the Israeli real-estate company ICOM.

Gal Einai’s younger, more dynamic journalistic sister is the Jewish Voice, a media outlet that gives Ginsburgh-inspired instant explanations for current events as they unfold. In late summer 2015 the firebombing of the Dawabsheh family’s home in Duma moved Israeli security forces to conduct a sweep of suspected Jewish terrorists. Quickly, the Jewish Voice promoted a widely circulated petition calling for their release. Ginsburg’s name was the first in the long list of established rabbis on the public petition.

Ginsburgh has also penned more than 80 books in Hebrew and English. And while the Israeli public is most familiar with popular booklets that address controversial political topics — such as the occasions on which it is permissible to kill non-Jews — the lion’s share of his work is broader and deeper; he has written books on Jewish law, religion and science, Kabbalah, psychology, love, marriage and education. He even wrote a children’s book. Over his five-decade career Ginsburg has forged a comprehensive religious doctrine that touches each and every aspect of human life. His ideas strike even some of those who despisehis political views as beautiful and profound.

“Rabbi Yitzchak Ginsburg is a paradox,” Ohad Ezrahi, a former student, wrote in a 2013 Haaretz article. “On the one hand he is a brilliant thinker, an innovator, has a great sense of humor, wide knowledge of Kabbalah as well as the sciences. On the other hand, this person disseminates racist and violent preaching.”

The Forward sought to obtain an interview with Ginsburgh multiple times over a six-month period during the reporting of this story, through the political movement he heads, a public relations official organizing his Tel Aviv event and several of his closest students. Ginsburgh, who is known to avoid contact with the press, did not respond.

Basok, the Ginsburgh acolyte following his every word at the Tel Aviv rally, typified the path taken by many of his supporters. Brought up in a lower-middle-class Orthodox family in the alleys of Jerusalem’s Old City, he didn’t like to study Torah that much early on, he said; it bored him. But when he was 19 someone invited him to hear Ginsburgh give a shiur, or rabbinic lecture, in the Old City.

Fascinated, he barely noticed that several hours had passed by the time it ended. Soon after, he visited Ginsburgh at his synagogue in Yitzhar, a hard-line West Bank settlement, and then became a student there in Ginsburgh’s Od Yosef Chai yeshiva.

Ginsburgh’s own path from a traditional Jewish community in St. Louis to the forefront of Israel’s radical religious fringe is partly unknown, partly clouded by myths. The way Ginsburgh’s followers tell it, the future kabbalist became a ba’al teshuvah, or returnee to traditional Judaism, at the age of 14 after a striking encounter with a Hasidic Jew. Others, who knew him later in life, say that it was a rabbi in Philadelphia who paved Ginsburg’s path to Torah when he was 18 or 19.

In every account, Ginsburg’s brilliance was, from early on, beyond dispute. At 19 he graduated from the University of Chicago with a degree in mathematics and philosophy, and at 20 he was working toward a master’s degree in mathematics at Yeshiva University in New York. Yet despite taking 30 credits and completing the M.A. in a single year, Ginsburgh focused most of his energy on Torah.

Rabbi Dov, who insisted on a pseudonym, was Ginsburg’s study partner and only friend that year in New York. Like many interviewees for this article, he didn’t want to be publicly associated with Ginsburgh because of the latter’s radical ideas. At the time, Dov, who grew up Orthodox, was studying for his ordination, yet spent part of his time on most days learning Torah with his quiet math student partner. Ginsburgh also found the time to audit classes of Rabbi Joseph B. Soloveitchik, Y.U.’s renowned Torah scholar and philosopher, he related.

In 1965, Ginsburgh immigrated to Israel, where he lived in Jerusalem and continued to immerse himself in his studies. Then, after the 1967 Six-Day War he was part of a small group that pioneered the revival of the Jewish Quarter in the Old City of Jerusalem.

It was also around this time that Ginsburgh discovered Chabad. The encounter inspired him to journey to the heart of the movement, in the Crown Heights section of Brooklyn. He stayed in New York for a few months and studied with Rabbi Menachem Mendel Schneerson, the sect’s influential grand rabbi.

The experience transformed him; to this day he considers himself part of Chabad even though, to a significant extent, he has diverged from the Chabad doctrine and created one of his own.

Today, Ginsburgh and Schneerson resemble each other. Ginsburgh’s long white beard, pale skin, black Chabad attire and even his gestures — like raising a hand to emphasize a crucial point, or his concentrated nod when music is playing — are reminiscent of Schneerson. His ties with the sect remain close.

There is another similarity: Schneerson was routinely hailed by his acolytes as the Jewish messiah whose coming was predicted by bibilical prophets, but never publicly accepted or disavowed these beliefs. Similarly, Ginsburgh’s followers do not just support his calls for an Israeli monarchy; they believe he should hold the crown. But Ginsburgh has carefully avoided either confirming or disavowing his interest in the position.

In the late 1960s, Ginsburgh returned to teach in Jerusalem, where he got married and eventually moved to Kfar Chabad, the Chabad-only village near Lod in central Israel, where he eventually raised six children. And by the early 1970s, he was amassing a following. “He was kind of their guru,” said Dov, who moved to Israel himself around that time and reconnected with his former study partner. These early disciples seemed to gravitate toward Ginsburgh, who exuded a spiritual self-confidence, Dov said.

By the early 1980s, Ginsburgh was quickly becoming a leader among the West Bank radical youth. In 1983 he helped found the Od Yosef Chai yeshiva in the Palestinian city of Nablus. And in 1989, 30 of Ginsburgh’s students went on a rampage in the village of Kifl Hares near Nablus shooting and killing a 13-year-old Palestinian girl. Ginsburgh testified on their behalf in an Israeli court, saying, “It should be recognized that Jewish blood and a goy’s [non Jew’s] blood are not the same.” It is a phrase that he would repeat, in one iteration or another, time and again.

In 1994, the American-born settler, Goldstein, murdered 29 Palestinian Muslims in Hebron as they knelt in prayer at the Cave of the Patriarchs, where, according to tradition, the biblical figures Abraham, Isaac, Jacob and their wives — all of them revered also in Islam — are buried. Soon after, Ginsburgh wrote his most infamous work: a pamphlet titled “Baruch Ha Gever,” or “Blessed Is the Heroic Man,” that investigates the spiritual and moral virtues of Goldstein’s massacre. The title, perhaps not incidentally, also invoked Goldstein’s own first name, suggesting he was the heroic man. “The life of Israel is more important than the life of goyim,” Ginsburgh wrote there. “If there is a chance (even a slight one) that the goy will work (even indiscreetly) to harm the life of Israel, then you don’t care for the life of the goy — moreover the best goy is a dead one.”

Ginsburgh’s pamphlet inspired the publication of a collection of articles in a book, also entitled “Baruch Ha Gever,” that explored the permissibility of killing Arabs according to Jewish law. The editors of the books were convicted of incitement for racism in 1996. In April of that same year, Ginsburgh gained notice in American Jewish circles when he told the New York Jewish Week that Halacha, or traditional Jewish law, would “probably permit” seizing an unwilling non-Jew for a liver transplant to save the life of a Jew.

“Jewish life has infinite value,” he told the newspaper. “There is something infinitely more holy and unique about Jewish life than non-Jewish life.”

In March 1996, Ginsburg was detained without charge or trial — a practice usually reserved exclusively for Arabs — for 60 days on the direct order of Prime Minister Shimon Peres. The state cited him as an immediate threat when, after a spate of terrorist attacks, he allegedly told his students that it was “imperative under Jewish law to revenge the Arabs.” In his appeal, Ginsburgh didn’t deny these words; he instead argued that his praising of revenge against Arabs, “… isn’t enough to assume — at least not to the needed degree of probability — that because of these words his students will harm Arabs.”

Debriefing the Knesset three days after the detention order, Minister of Internal Security Moshe Shahal said: “Yitzchak Ginsburgh is one of the most extreme of the so-called rabbis. He consistently preaches for revenge, he justified the massacre at the Tomb of the Patriarchs…. He has influence over his followers, who see his interpretation of Jewish law as a permission, and even an instruction, for action.”

But less than three weeks later, Supreme Court Judge Dalia Dorner ordered Ginsburgh’s release. She criticized Peres’s administrative detention order, saying that “it was never proved that his statements… may bring his students to attack Arabs.”

Since then, some of Ginsburgh’s students have been accused and jailed countless times for attacking Arabs, in some cases, shooting and seriously wounding them. But authorities have been frustrated in proving a link between something Ginsburgh said and a specific violent action.

“In my personal opinion, [Ginsburgh’s] words count as incitement and he should have faced charges a long time ago,” Carmi Gillon, a former head of the Shin Bet, Israel’s domestic security and intelligence service, told the Forward in a phone interview. “The argument against charging him is that it is impossible to draw a direct line between something he said and a specific terror attack. But this is the crux of the issue: Oftentimes in the case of incitement, there is no smoking barrel and we need to trust other evidence.”

The rabbi first moved to Yitzhar in 2001, when the Israeli army, as part of the Oslo peace agreement, withdrew from Nablus, where his Od Yosef Chai yeshiva had previously been located, at a site reputed by legend to be the burial place of the biblical patriarch Joseph. Yitzhar is known as one of the most extreme West Bank Jewish settlements, and as if in line with his new location, Ginsburgh publicly called at the time for a “revolution” and a “new Jewish country” where Jewish law would replace secular government. Israel’s security services raided the school in 2010, after publication of “The King’s Torah,” a book by two of Ginsburgh’s top disciples there that justifies the killing of non-Jews, including infants, if there is reason to believe they will grow up to harm Jews.

For Ginsburgh, “The secular Zionist enterprise is the shell before the fruit,” meaning the redemption, said Shlomo Fischer, an Israeli sociologist who has studied his work. “The Israeli government is basically evil. It is preventing the redemption. So what he is saying is that we need something totally different.” To Ginsburgh’s followers, the rabbi himself is the only one who can bring that about.

The extent of his followers’ devotion is displayed at his events. This past March, during Purim festivities on the third floor of a synagogue in the Nachlaot neighborhood in Jerusalem, some of his students were singing and dancing. “You know who this is?” one of them asked another. Before his friend could reply, he answered: “The rabbi is the Messiah King! He is our king and our Messiah.” Eliyahu Pelee, the 22 year-old son of one of Ginsburgh’s closest students, who was raised in Yitzhar, told the Forward that for his followers, Ginsburgh is unquestionably the person for the job of monarch.

In the past 10 years, Ginsburgh has somewhat toned down his violent rhetoric, even decrying the use of violence to achieve the truly Jewish state of which he dreams. But his influence continues through his students. In June 2014, security officials were cited in an article in the Israeli daily Haaretz blaming a spate of vengeance attacks on a group of about 100 radical activists in Yitzhar who based their actions on Ginsburgh’s teachings.

Duma, site of the arson attack that killed the three Dawabsheh family members, lies between Yitzhar and Kfar Tapuach, a stronghold of followers of Rabbi Meir Kahane, the late right-wing Brooklyn-born religious nationalist. Kahane advocated mass expulsion of all Arabs from Israel and the West Bank and, in a kind of fateful convergence, one of the prize students to emerge from Ginsburgh’s yeshiva is Meir Ettinger, a Kfar Tapuach native and Kahane’s own grandson. Today, Ettinger has come to prominence as a radical anti-state ideologue in his own right while remaining a close associate of Ginsburgh. In a blog post last year, Ettinger advocated strategically driving the Israeli Palestinian conflict toward “expulsion” of non-Jews. Israeli authorities believe he is the leader of a group called The Revolt — a West Bank cell that aims to overthrow the state—and jailed him without charge or trial in July 2015. He was released only this past February.

In a recent rare interview, Ettinger’s wife said, “All of [Ettinger’s] ideas are advised by the Torah’s opinion, especially by Rabbi Yitzchak Ginsburgh; he gets all of his ideas from him [Ginsburgh] and tries to be his shofar.”

Naomi Zeveloff contributed reporting to this article.