The Viper and the File

He that a greater biter bites, His folly on himself requites, As we shall manifest forthwith.- There was a hovel of a smith, Where a poor Viper chanced to steal, And being greedy of a meal, When she had seized upon a file, Was answer'd in this rugged style: " Why do you think, 0 stupid snake! On me your usual meal to make, Who've sharper teeth than thine by far, And can corrode an iron bar ?"