How could I find enough leather
To cover the earth?
Having leather on the soles of your sandals
Is the same as covering the whole earth.
— Shantideva (Engaging in the Deeds of Bodhisattvas)
Check whether or not you could ever completely subdue your enemies. You will [find that you would] never run out of enemies or subdue them all before the time came when there were no sentient beings left. But if you subdue your anger you will not have a single enemy, and it will be the same as subduing all your enemies.
Once you thoroughly understand how the types of patience are classified by their nature, plus the drawbacks of anger and so forth, will you ever again let your whole body be possessed by anger? Once a lama tried to separate his disciple and a thief in a fight. He did not succeed and the disciple was hitting the man. The lama put his finger on his disciple’s nose and said, “Patience! Patience!” Immediately the disciple recalled his lost patience. What use is it to pretend to be patient if your anger has already done its work? It will be difficult at first to be patient; it will become easy if you familiarize yourself through mind training.
There are reasons why it is not right to get angry with someone who does you harm. Suppose a man hits you on the head with a club. Think as follows to stop yourself becoming angry: “If I must be angry with the thing that actually causes the pain, I should be angry with the club. But the club itself is powerless, it is being used.” The man hitting you is powerless, too. He is being forced to do this by the delusions in his mindstream. It profits you little to be angry with them, so it is wrong to be angry. It all comes down to one thing: the wrong way you behave is the most immediate casual factor your your being hit with the club. The roots, however, is the evil karma you acquired through hurting people in the past, and so forth. So, since this resulted from the ripening of your own actions through cause and effect, with whom should you be angry?
Liberation in the Palm of Your Hand: A Concise Guide on the Path to Enlightenment