The existent in the nonexistent; The nonexistent in the non-nonexistent; The form in the formlessness; The emptiness in the nonemptiness. For the nonexistent is the existent. And the non-nonexistent is the nonexistent. Formlessness is verily form; Nonemptiness is verily emptiness. Emptiness is indeed emptiness; Form is indeed form. Form has no fixed form; Thus form is emptiness. Emptiness has no fixed emptiness; Thus emptiness is form. The knowledge of emptiness is not emptiness; The knowledge of form is not form. When names and action mutually illuminate. Then one has reached the wondrous sound. - A discourse by Tathāgata from Journey to the West Vol. III, Ch. 58, p. 129