A new translation of the Quran, with commentary, is causing a stir—and maybe something of a revolution—in the world of English-speaking Muslims.

Why’s that? Because Salafists—adherents of a very conservative brand of Islam—have dominated the world market for Qurans for decades.

Funded by the oil-rich royal family in Saudi Arabia, which has an especially rigid Wahhabi branch of Islam, the Salafis have exported their teachers, their mosques, their audio and video productions, and religious texts across the Arab world and into Pakistan, Europe, and North America, quashing alternate interpretations that don’t fit their narrow views.

“In all these places, they funded the building of Saudi-style mosques with Wahhabi preachers and established madrasas that provided free education for the poor, with, of course, a Wahhabi curriculum,” religious scholar Karen Armstrong wrote about the Saudi export of religion in 2014. “At the same time, young men from the poorer Muslim countries, such as Egypt and Pakistan, who had felt compelled to find work in the Gulf to support their families, associated their relative affluence with Wahhabism and brought this faith back home with them, living in new neighborhoods with Saudi mosques and shopping malls that segregated the sexes.”

Seeing this new translation as a challenge to their orthodoxy in English-speaking countries, Salafis are none too pleased. In online discussions and reviews, influential Salafis are panning the volume, called The Study Quran, as a soft-bellied facsimile that might be fine for academia, but not fit for following.

In fact, this no mere academic debate. Followers of the Saudi-Wahhabi-Salafi version of Islam in Europe and the United States are increasingly seen by law enforcement as a pool from which radical jihadis can draw recruits.

Some strains of this Salafi interpretation have popularized takfirism—the practice by which some Muslims declare that others are not true believers. The aftereffects are clear in fringe jihadi groups like the self-declared caliphate that calls itself the Islamic State, where those who believe differently are deemed apostates who can be, and are, slaughtered en masse. The vast majority of Salafis are not jihadis and not takfiris. But those who are use their understanding of their Quran to justify killing Shia Muslims, Yazidis, adulterers, gays, and anyone else who runs afoul of their zealotry.

Generations of the world’s Muslims have, now, grown up in the shadow of this Saudi religious empire, ignoring previous centuries of rigorous religious discourse, debate, and dissent.

The Study Quran, setting the record straight, may come as something of a revelation to Muslims and anyone else interested in Islam who speaks English. It is a formidable academic endeavor, and since it was published in November it has been flying off the shelves in a massive hardback edition. (It is also available now on Kindle.)

The editors have compiled a new translation, new commentary, and drawn on dozens of the most prominent mufassirs (interpreters or exegetes), many of whom have never before been accessible to an English-speaking audience. Indeed, “very few” of the sources cited in The Study Quran are available in English translation, head editor Seyyed Hossein Nasr told The Daily Beast.

One soon comes across nuances that are unmentioned or ignored by extremists. The Study Quran notes, for instance, that verse 47:4—used by ISIS to justify beheadings—focuses on “the brevity of the act, as it is confined to battle and not a continuous command.” This interpretation would seem to challenge extremists who attempt to carry out such acts on civilians, whether on the streets of London or in Syria.

The Salafi scholars who have monopolized English-language Muslim resources are disturbed and even frightened by this textual revolution that puts them back in their place.

Salafism “was not in the mainstream of the Muslim tradition,” said Nasr. “It rejected centuries of Islamic thought.” The scholars contributing to The Study Quran, who are both Sunni and Shia, also break with the ultra-Orthodox animus against Shiism.

The Study Quran’s rich commentary, crowding around a few verses on any given onion-paper page of the hardback edition, seeks to remedy the previous absence of solid historical discourse. After all, Nasr said, even centuries ago the yearly pilgrimage to Mecca meant that exegetes, or interpreters of holy texts, were able to have a much richer exchange of ideas—and much more knowledge of one another—than European thinkers of the time.

It’s no surprise then, that Abu Eesa Niamatullah—a British Salafi with a large social media presence—cautioned followers tempted by The Study Quran to “avoid it. Like the plague.”

“It doesn't just have mistakes, it's actually dangerous,” Niamatullah said. “This is advice to the 99 percent of people here, those who don't have the detailed tools necessary to separate the wheat from the chaff.”

Though Sunni Islam formally lacks a clerical class, Niamatullah expressed concern that those who lack proper religious or academic training might be swayed from the orthodox path by the new edition.

“My point being that I see it as absolutely a threat to orthodox Sunni creed that such translations and commentaries, but more importantly, such deviated individuals such as Nasr being given a prominent platform to the hearts and minds of the basic masses who can't filter through the nonsense like you can,” he added in a comment.

A more moderate review, recommended by prominent cleric Yasir Qadhi to hundreds of thousands of followers on social media, acknowledges that the rigor of The Study Quran “is apparent after even a cursory reading,” but nonetheless it “is an academic and educational work, and as such includes commentaries from sources that may not be considered orthodox depending on one’s denominational orientation.” (Qadhi recently distanced himself from the Salafi label and critiqued some aspects of the movement.)

“Some of the Sufi commentaries can come off as uncomfortably esoteric,” the author Mobeen Vaid writes. “Khārijite positions are occasionally expounded upon, and not for the purpose of refutation.” (Kharijites were a rebel sect in the first century of of Islam.)

The differences that make it suitable for academia but not practice go all the way down to the understanding of the very nature of the Quran. “For believers,” says Vaid. “the Quran doesn't say anything, God does.”

And yet, The Study Quran fills part of what some scholars see as a perpetual hole in the study of Islam. Quranic translations abound, but centuries of commentary, debate, and context have long been the exclusive domain of those with a strong command of Arabic.

"We appear to be amidst a deluge of English translations of the Quran," Scott Lucas, a professor at the University of Arizona, wrote in 2014, reflecting on the proliferation of translations in the prior decade.

Pretty much any Quran given out in a da’wa, or religious outreach, program almost anywhere in the world has its roots in Saudi Arabia. Most of them use a translation completed by Yusuf Ali, an Indian-born, British-educated scholar who died in the mid-20th century. Published in 1938, it included not only Ali’s translation, but also parenthetical commentary on meaning—much of which has been stripped out by its Salafi adapters.

The first Quran ever owned by this reporter was an Ali translation, distributed through a Chelsea-based da’wa program to a bank teller, who unloaded it to this student of religion when she was still a teen. The thick hardcover has the scripture in two varieties: the original Arabic, as well as an English translation.

(Significantly, The Study Quran, already voluminous, does not include the original Arabic, the language in which Allah delivered his message to Muhammad. But the Arabic text is now readily available online and in many smaller volumes for comparison.)

Ali wasn’t the first translator of the Quran into English, of course. One of the earliest widely available translations was by George Sale, and it served as the standard for nearly two centuries. It’s rife with annotations that point to Sale’s Christian understanding of the “Mohammedan’s” holy scripture. More recent translations have come from feminists and creative translations that assign each Arabic word one—and only one—English equivalent.

And The Study Quran surely won’t be the last. The authors’ main goal, after all, is not a definitive translation—but a demonstration that different interpretations were “established, well known, and rigorously discussed over the centuries,” Nasr said.

This article has been updated.