摩訶止觀 3.194

3.194

又《大論》明摩訶衍人體法觀者，引佛在一方木上，告諸比丘：「譬如比丘得禪定時，變土為金，變金為土；實非金土，變化所為。」色、心亦如是，非生非滅，無明變耳。本自不生，今那得滅。又引觀一端㲲，即具十八空，是名「體法觀」。

Furthermore, the Mahāprajñāpāramitopadeśa clarifies the contemplation embodying dharmas of a practitioner of the Mahāyāna by citing the Buddha, who, seated upon a square block of wood, addressed the monks: 'For example, when a monk attains dhyāna concentration, he turns earth into gold and turns gold into earth; in reality it is neither gold nor earth, but produced through transformation.' Form and mind are also like this: they are neither arising nor perishing, but merely transformed by avidyā. Fundamentally they do not arise; how could they now perish? It also cites that contemplating a single piece of cotton cloth possesses the eighteen kinds of emptiness; this is named the 'contemplation embodying dharmas.'