Eknath Easwaran's Commentary
In meditation, we learn the skill of bringing our attention back to the words of the inspirational passage whenever it strays away. Attention is like a restless puppy, fond of running after anything new that comes along. When it sees an intensely charged memory, it cannot let it roll by; it has to chase the memory and keep yapping, yapping, yapping.
Just as with a dog, we have to call the mind back over and over again, whenever we sit down for meditation. This may go on for years. But if we keep practicing diligently and systematically, the day will come when we can put our attention where we want it with little effort, and it will stay without movement or protest. Then, however unkind somebody may have been, we will not be mastered by resentment; our attention will not turn to the past at all.