( The Buddha // Kakacūpama Sutta, Pali Canon )
When others address you, their speech may be timely or untimely, true or untrue, gentle or harsh, connected with good or connected with harm, spoken with a mind of loving-kindness or with inner hate.
Wise ones, suppose a man came with a blazing grass-torch and said : ‘I shall heat up and burn away the river Ganges with this blazing grass-torch.’ What do you think? Could that man heat up and burn away the river Ganges with that blazing grass-torch?” ― “No, Buddha” ― “Why is that?” ― “Because the river Ganges is deep and immense; it is not easy to heat it up and burn it away with a blazing grass-torch. Eventually the man would reap weariness and disappointment.”
So too there are these five courses of speech. Herein, wise ones, you should train thus : ‘Our minds will remain [like the river Ganges] unaffected, and we shall utter no evil words; we shall abide compassionate for their welfare, with a mind of loving-kindness without inner hate. We shall abide pervading that person with a mind imbued with loving-kindness, and starting with them, we shall abide pervading the all-encompassing world with a mind imbued with loving-kindness, abundant, exulted, immeasurable, without hostility, and without ill-will.’ That is how you should train, O wise ones.