Suppose, a man, who can see, were to behold the many bubbles on the Ganges as they are driving along. And he should watch them and carefully examine them. After carefully examining them, they will appear to him as empty, unreal, and unsubstantial. In exactly the same way does the monk behold all the bodily forms, feelings, perceptions, mental formations and states of consciousness. Whether they be of the past, or the present, or the future, far or near. And he watches them and examines them carefully, and, after carefully examining them, they appear to him as empty, void and without an Ego.

(Buddha Sakyamuni)