Huon de Bordeaux
encounters in Syria an old follower of the family named Gerasmes (2 syl.), whom he asks the way to Babylon. Gerasmes told him the shortest and best way was through a wood sixteen leagues long, and full of fairies; that few could go that way because King O'beron was sure to encounter them, and whoever spoke to this fay was lost for ever. If a traveller, on the other hand, refused to answer him, he raised a most horrible storm of wind and rain, and made the forest seem one great river. “But,” says the vassal, “the river is a mere delusion, through which anyone can wade without wetting the soles of his shoes.” Huon for a time followed the advice of Gerasmes, but afterwards addressed Oberon, who told him the history of his birth. They became great friends, and when Oberon went to Paradise he left Huon his successor as lord and king of Mommur. He married Esclairmond, and was crowned “King of all Faerie.” (Huon de Bordeaux, a romance).
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894