Enlightenment originally has no duality, yet expedients are countless. The countless expedients are summarized in three. Quiescence is like a clear, bright mirror. Illusion-contemplation is like a shoot growing out of the ground. Dhyana is like the sound within the bell. Although these three dharma-gates have distinctions of deep and shallow, in their relation to Perfect Enlightenment, the are all called "accordance." The buddhas and bodhisattvas accomplish the Way based on these. The complete realization of the three is called Great Nirvana.
Kihwa's commentary on the Sutra of Perfect Enlightenment, p. 181.