The Viper and the File

The Fables of Phædrus
Let him who with greedy teeth attacks one who can bite harder, consider himself described in this Fable.
A Viper came into a smith’s workshop; and while on the search whether there was anything fit to eat, fastened her teeth upon a File. That, however, disdainfully exclaimed “Why, fool, do you try to wound me with your teeth, who am in the habit of gnawing asunder every kind of iron?”