The following is respectfully quoted from “Enlightened Courage” by His Holiness Dilgo Khyentse Rinpoche:
There is a story that one day, when Maitriyogin was teaching, a dog barked at someone, who, losing his temper, threw a stone at it. The dog was hit in the ribs and yelped. Feeling great sorrow for the animal, the teacher cried out and fell down from the throne. “This is taking things a bit too far,” thought his disciples. Knowing what was in their minds, Maitriyogin said, “Look here, at my ribs.” And on his body, exactly where the stone had hit the dog, he had a bruise. He had taken the suffering of the animal upon himself.