Vernon Jones (1912)
157. THE FARMER AND THE VIPER
One winter a Farmer found a Viper frozen and numb with cold, and out of pity picked it up and placed it in his bosom. The Viper was no sooner revived by the warmth than it turned upon its benefactor and inflicted a fatal bite upon him; and as the poor man lay dying, he cried, "I have only got what I deserved, for taking compassion on so villainous a creature."
Kindness is thrown away upon the evil.
Aesop's Fables: A New Translation by V.S. Vernon Jones with illustrations by Arthur Rackham (1912). This book is available online at Project Gutenberg.