The proverb is spoken by Attic authors in reference to things that are unattainable and non-existent,[1] as are the following: "washing a brick", "plucking a wineskin", "painting a cookpot", "burning incense on manure". But Aristarchos [derives the saying] from the fact that Kratinos portrays someone brading a rope in Hades, and an ass eating what has been braided, i.e. shearing it off.[2]
Thus, inasmuch as things in Hades are unattainable, this was invented.[3]