This is an anagram that is said to come from an unknown medieval writer. Readers of the New Testament will recall that, when Christ was taken before Pilate as a criminal, He said, "To this end was I born, and for this cause came I into the world, that I should bear witness unto the truth. Every one that is of the truth heareth my voice."
When Pilate asked, "What is truth?" (Quid est veritas?) there is no indication that Christ replied; however, the medieval anagrammatist pointed out that, strangely enough, the question contained its own answer. A rearrangement of Quid est veritas gives us Est vir qui adest (It is the Man who is here); in other words, Christ Himself is the Truth (John 18:37-38).