“Wet your Whistle” may also be traced again to the medieval vintage of Geoffrey Chaucer, The Canterbury Stories, the place the word was once first incorporated, within the aforementioned shape.
The expression is metaphoric in nature, associating a person’s lungs and breathing machine with a whistle, which blows higher, when it’s rainy.
The debated change shape didn’t get up till the 1600s, when the phrase “Whet” was once presented into the English dictionary, meaning “to sharpen.” Since then, the controversy, regarding the real type of the expression has been prevailing in pubs and taverns.