Akkosa SuttaI have heard that on one occasion the Blessed One was staying near Rajagaha in the Bamboo Grove, the Squirrels' Sanctuary. Then the brahman Akkosaka Bharadvaja heard that a brahman of the Bharadvaja clan had gone forth from the home life into homelessness in the presence of the Blessed One. Angered & displeased, he went to the Blessed One and, on arrival, insulted & cursed him with rude, harsh words.
When this was said, the Blessed One said to him: "What do you think, brahman: Do friends & colleagues, relatives & kinsmen come to you as guests?"
"Yes, Master Gotama, sometimes friends & colleagues, relatives & kinsmen come to me as guests."
"And what do you think: Do you serve them with staple & non-staple foods & delicacies?"
"Yes, sometimes I serve them with staple & non-staple foods & delicacies."
"And if they don't accept them, to whom do those foods belong?"
"If they don't accept them, Master Gotama, those foods are all mine."
"In the same way, brahman, that with which you have insulted me, who is not insulting; that with which you have taunted me, who is not taunting; that with which you have berated me, who is not berating: that I don't accept from you. It's all yours, brahman. It's all yours.
"Whoever returns insult to one who is insulting, returns taunts to one who is taunting, returns a berating to one who is berating, is said to be eating together, sharing company, with that person. But I am neither eating together nor sharing your company, brahman. It's all yours. It's all yours."
This is much better than "don't feed the troll", as it puts the responsibility on me, not the troll.
Don't accept food from the troll.