Phaedrus Phaedrus 
The Fables of Phædrus [EPUB ebook] 

Driven by thirst, a Wolf and a Lamb had come to the same stream; the Wolf stood above, and the Lamb at a distance below. Then, the spoiler, prompted by a ravenous maw, alleged a pretext for a quarrel. ‘Why, ‘ said he, ‘have you made the water muddy for me while I am drinking?’ The Fleece-bearer, trembling, answered: ‘Prithee, Wolf, how can I do what you complain of? The water is flowing downwards from you to where I am drinking.’ The other, disconcerted by the force of truth, exclaimed: ‘Six months ago, you slandered me.’ ‘Indeed, ‘ answered the Lamb, ‘I was not born then.’ ‘By Hercules, ‘ said the Wolf, ‘then ’twas your father slandered me;’ and so, snatching him up, he tore him to pieces, killing him unjustly.
This Fable is applicable to those men who, under false pretences, oppress the innocent.