Dhammapada 42 [Khuddaka Nikaya]

3 - Cittavagga, The Mind
8 - Nandagopalaka Vatthu

Diso disam yam tam kariya, veri va pana verinam;
micchapanihitam cittam, papiyo nam tato kare.

42: A thief may harm a thief; an enemy may harm an enemy; but a wrongly directed mind can do oneself far greater harm.
Reference:
Mya Tin, Daw, tr. The Dhammapada: Verses and Stories. Rangoon: Burma Tipitaka Association,1986.
 
Posted by Nyan U