Kakacupama Sutta: The Simile of the Saw (Majjhima Nikaya 21)
Our minds will be unaffected and we will say no evil words. We will remain sympathetic, with a mind of goodwill, and with no inner hate. We will keep pervading these people with an awareness imbued with goodwill and, beginning with them, we will keep pervading the all-encompassing world with an awareness imbued with goodwill — abundant, expansive, immeasurable, free from hostility, free from ill will.
That's how you should train yourselves.
Our minds will be unaffected and we will say no evil words. We will remain sympathetic, with a mind of goodwill, and with no inner hate. We will keep pervading these people with an awareness imbued with goodwill and, beginning with them, we will keep pervading the all-encompassing world with an awareness imbued with goodwill — abundant, expansive, immeasurable, free from hostility, free from ill will.
That's how you should train yourselves.