摩訶止觀 7.63

7.63

若通教，明苦集皆如幻化即空門。古《釋論》本云：「若觀極微色，則有十八空。」今本云：「若觀一端疊，則有十八空。」疊是假名，極微是實法，以此為異。若得意者，假、實皆空耳。若未入空，情想戲論，計有空相；知空無空相，名「無相門」。空相雖空，猶計觀智，既無能所，誰作空觀？是名「無作門」。既無作者，誰起願求？亦名「無願」。此三三昧王臣（云云）。

Under the shared teaching, it explains that suffering and origin are both like illusions and transformations, which is the gate of emptiness. The old version of the Mahāprajñāpāramitopadeśa says: 'If one contemplates subtle material form, then there are the eighteen emptinesses.' The current version says: 'If one contemplates a single bolt of cloth, then there are the eighteen emptinesses.' A bolt of cloth is a provisional designation, while subtle form is an actual dharma; herein lies their difference. If one grasps the meaning, both the provisional and the actual are empty. If one has not yet entered emptiness, conceptualizing through emotional thought, one conceives of a sign of emptiness; knowing that emptiness has no sign of emptiness is termed the 'gate of signlessness'. Although the sign of emptiness is empty, one still conceives of the contemplative wisdom; since there is neither subject nor object, who performs the contemplation of emptiness? This is termed the 'gate of wishlessness'. Since there is no agent, who gives rise to aspiration and seeking? It is also termed 'wishless'. These three samādhis are king and minister (and so forth).