Great Mischief, Great Service
42. Whatever a hater may do to a hater, or an enemy to an enemy, a wrongly-directed mind will do us greater mischief.
43. Not a mother, not a father will do so much, nor any other relative; a well-directed mind will do us greater service.
From the chapter Thought in Sacred Books of the East, Vol. 10: The Dhammapada and Sutta Nipata, by Max Müller and Max Fausböll, [1881].
http://www.sacred-texts.com/bud/sbe10/sbe1006.htm