A highly respected lama once told me about his own meditations on loving-kindness and their effects on his life. He was imprisoned for over twenty years, doing hard labor and building roads. He worked laying bricks and putting on roofs six days a week. One might think he would have been unhappy, but he said, "I don't remember being sad or angry even once during all those years. I focused my mind mainly on two meditations. I meditated on compassion, instead of harboring hatred toward our prison guards, because I knew they were accumulating such grave karma by causing pain to so many people that their future lives would be horribly painful." "I also meditated on joy for the opportunity to be relieved of some of my own karmic debts. The pain that I faced was certainly the result of my own misdeeds in past lifetimes. Now I had the opportunity to exhaust the negative karmas by enduring those consequences. So it was a joyful time too."
He is such an honest and helpful human being, and a great scholar and meditator, that by the power of his meditation on compassion and joy, therefore, he remained healthy and sane while in prison, and he came out shining with greater peace and joy than before he was imprisoned.
Excepted from: The Healing Power of Loving-Kindness; A Guided Buddhist Meditation, Tulku Thondup, Shambhala Publications