Why can't faeries lie?
 

Does anyone know the origin of that myth? Whenever I've read any fantasy books that have faeries as some of the characters they always say how they can never lie. And I've always wondered where that came from.

it in part goes back to the old belief that oaths had power, and that to break one was to break certain rules of both society and religion- certain powerful beings were ascribed the inability to lie, as it was their job to enforce oaths.. hence swearing by whatever god, through the ages.... also, certain evil powers, down through the chrisitan devil, have been known as the father or mother of lies....