You must first liberate yourself from the past and future. If you can keep your mind on the present moment, then you are truly deriving strength and power from the practice. With power you can liberate yourself from the present moment as well. When you are liberated from time, you are also liberated from space. Space and time, like the five skandhas, are illusions. When you are free from space, time and the five skandhas, there is no self. If a self exists ─ whether it is a narrow self or a universal self ─ then craving, anger and ignorance also exist.