John Chrysostom: Let Your Heart Learn From Your Tongue

In your case, therefore, dearly beloved, imitate this man, and learn this lesson first, never to use scurrilous names of your foe, but respectful ones; should your mouth be in the habit of calling your aggressor by names that are respectful and betoken service, the soul on hearing this will learn from the tongue, become accustomed and undergo a change of heart towards him. The words themselves will be the best remedy for the heart's choler.

- John Chrysostom (around A.D. 347 to around A.D. 407), Old Testament Homilies, Volume 1, Homilies on David and Saul, Homily One, p. 24 (2003), Robert C. Hill translator.