From this point on you really know. This is called the pinnacle of Zen, the sovereignty of Zen. It is also called knowledge of what is knowable; it produces all the various states of meditation, and anoints the heads of all spiritual princes. In all fields of form, sound, fragrance, flavor, feeling, and phenomena, you realize complete perfect enlightenment. Inside and outside are in complete communion, without any obstruction at all.

- Pai-chang, "The Sphere of the Enlightened"