Gandalf speaks the line “You shall not pass!” in J.R.R. Tolkien’s The Lord of the Rings.
He says it while confronting the Balrog on the Bridge of Khazad-dûm in Moria. Gandalf stands between the creature and the rest of the Fellowship, declaring that the Balrog cannot cross. The bridge breaks, but the Balrog’s whip catches Gandalf, pulling him into the abyss.
In Tolkien’s narrative, Gandalf later returns as Gandalf the White after completing his struggle with the Balrog. The quotation became even more famous through Peter Jackson’s film adaptation, where Ian McKellen delivers it dramatically. The line is associated with Gandalf, not Aragorn or Boromir, who also defend the Fellowship at different points.