The meaning of Sarvasar, of the Sarvasar Upanishad is: the quintessential essence, the most foundational of all esoteric knowledge that has ever been discovered. In The Way beyond Any Way, Osho explains that understanding this one Upanishad will open doors to the ultimate truth. However, he also cautions that it is dangerous, like playing with fire, because an Upanishad cannot be completely understood without the reader becoming transformed. Look at it like this: some topics can be learned even if we remain as we are. No inner revolution is required to become a historian or a mathematician or a scientist. But religion is an entirely different matter. In religion, a transformation is needed before the knowing can be acquired. To encounter truth, even a little bit, is not a game; it is dangerous, because truth will not allow you to remain as you are. It will change, demolish, destroy and renew you. And this is what the Sarvasar Upanishad aims to do, to give you a new birth. Certainly there is pain in the birth, but without pain how can there be a new birth?