Monks, even if bandits were to savagely sever you, limb by limb, with a double-handled saw, even then, whoever of you harbors ill will at heart would not be upholding my Teaching. Monks, even in such a situation you should train yourselves thus: 'Neither shall our minds be affected by this, nor for this matter shall we give vent to evil words, but we shall remain full of concern and pity, with a mind of love, and we shall not give in to hatred. On the contrary, we shall live projecting thoughts of universal love to those very persons, making them as well as the whole world the object of our thoughts of universal love — thoughts that have grown great, exalted and measureless. We shall dwell radiating these thoughts which are void of hostility and ill will.' It is in this way, monks, that you should train yourselves.
Gautama Buddha
buddhism, kakacūpama, loving-kindness, maitri, majjhima-nikāya, mettā, sutra