The wise harm no one,
They are masters of their bodies
And they go to the boundless country,
They go beyond sorrow.
~The Dhammapada of Gautama the Buddha. CA. 500BC~
As you become a witness, as you become aware, you simply come to know that you are not the body, not the mind, not even the heart. You are simply a watcher, different from all that surrounds you. The body is your outermost boundary, the mind a little more inner, the heart still more inner, but at the innermost core you are just a consciousness.
Knowing this you become detached from your own body, your mind, your heart; and that detachment brings mastery. Not that you become destructive to the body -- you take every care of it, it is a beautiful instrument, it is a great gift of existence. But now you know that it is only the house you live in. Just as you take care of your house, you take care of your body; it is the temple.