One line within the traditional text, describing those who bow to vanity and emptiness, became the object of sustained controversy in medieval and early modern Europe, where some Christian authorities and converts from Judaism read it as a veiled insult directed specifically at Christian worship, an interpretation Jewish authorities generally denied, pointing instead to the phrase's older biblical resonance describing idolatry in general terms with no fixed reference to Christianity at all. Regardless of the line's original intended target, the controversy had lasting practical consequences: the phrase was removed or altered under censorship pressure in a great many printed prayer books across Christian Europe from the medieval period onward, and many communities, particularly in central and Western Europe, continued omitting or modifying it long after formal external censorship had lapsed, simply as an accepted local custom inherited from the censored editions.
The result today is real liturgical variation traceable directly to this centuries old controversy: some communities, particularly certain Sephardi and some Ashkenazi traditions less affected by the European censorship history, recite the full traditional line, while others recite an altered or shortened version reflecting the censored textual tradition their own prayer books descend from, so whether a given congregation says the disputed phrase in full is, in many cases, less a live theological choice being made today than an inherited trace of exactly which historical printing tradition their prayer book's text descends from.