Dhp 5

Dhammapadaṃ, 1. Yamakavaggo (The Pairs), Verse 5

na hi verena verāni | sammantīdha kudācanaṃ ||
averena ca sammanti | esa dhammo sanantano || 5 ||

5. For not by hatred are hatreds ever quenched here,
     but they are quenched by non-hatred. This is the ancient rule.

-- Translation by K.R. Norman from The Word of the Doctrine, p. 1
     The Pali Text Society, 2000