Women and elephants never forget an injury. Saki
If an injury has to be done to a man it should be so severe that his vengeance need not be feared. Niccolò Machiavelli
Never does the human soul appear so strong as when it foregoes revenge and dares to forgive an injury. Edwin Hubbell Chapin
Neglect will sooner kill an injury than revenge. Latin Proverb
Many an injury comes from a fool's speech. Latin Proverb
The memory of a benefit vanisheth, but the remembrance of an injury sticketh fast in the heart. Latin Proverb