Oysters open completely when the moon is full; and when the crab sees one it throws a piece of stone or seaweed into it and the oyster cannot close again so that it serves the crab for meat. Such is the fate of him who opens his mouth too much and thereby puts himself at the mercy of the listener.

Greene, Robert (2000). The 48 Laws of Power. Penguin Books. pp. 33. ISBN 0140280197.