You will know him when he comes to fulfill the prophecy
The Lisan Al-Gaib would never admit that he is the Lisan Al-Gaib
Background: A phrase used in the movie "Dune: Part Two" meaning "Off-World Prophet" or "Messiah". It was chanted each time Paul Atreides had proven himself in his role as their savior.
Meaning: In pop culture, it is used to describe someone who is, in that moment, at their peak.
Person 1: "He made the Jump!"
Person 2: "Lisan al Gaib!"
A Chakobsa term, the language of the Fremen people in Frank Herbert's Dune book series, that translates to "The Voice from the Outer World". The term refers to a visitor from another planet who would lead the Fremen to paradise, a prophecy implanted by the Bene Gesserit witches to control the Fremen. Paul Atreides / Paul Muad'Dib takes up the title in the first book in the series.
He knows our ways as if born to them, he must be the Lisan Al-Gaib!