Once on a time a partridge was sitting in a lofty tree. A fox came up, and began thus to speak: "O partridge, how beautiful is your aspect! your beak transcends the coral; your thighs the brightness of purple. and then, if you were to sleep, how much more beauteous you would be." As soon as the silly bird had closed her eyes, that instant the fox seized the credulous thing. Suppliantly she uttered these words, mingled with loud cries: "O fox, I beseech you, by the graceful dexterity of your exquisite skill, utter my name as before, and then you shall devour me." The fox, willing to speak, opened his mouth, and so the partridge escaped destruction. Then said the deluded fox: "What need was there for me to speak?" The partridge retorted: "And what necessity was there for me to sleep, when my hour for sleep had not come?" 
This is for those who speak when there is no occasion, and who sleep when it is requisite to be on the watch. 