There is an Arabian fable which tells about a man who went to his neighbor and asked to borrow a rope. "I can’t lend it, because I am using it to tie up a pile of sand." his neighbor answered.
"But," the man came back, "you can’t tie up a pile of sand with a rope."
To which his neighbor slyly replied, "Oh, yes you Can. In fact, you can do anything with a rope when you do not wish to lend it to your neighbor."