摩訶止觀 9.115

9.115

觀根本無四句，不生不滅，即畢竟空。此空具十八空；十八空祇是一空。《方等》云：「小空、大空皆歸一空。」《大品》云：「一獨空。」是名「空解脫門」。皆入此空，不取法性四相，不受、不著、不念、不分別新、舊、內、外（云云）。若心無依倚，以無所見見真佛性，以不住法住大涅槃，是名「無相解脫門」。是大涅槃，非修非作，非自故非因，非他故非緣，不共故非合，非無因故非離，無修無得，名「無作解脫門」。

Contemplating that the root has no four propositions, neither arising nor ceasing, is ultimate emptiness. This emptiness possesses the eighteen emptinesses; the eighteen emptinesses are just a single emptiness. The Vaipulya sūtras state: "Lesser emptiness and great emptiness all return to the single emptiness." The Larger Prajñāpāramitā states: "The sole, unique emptiness." This is called the "liberation gate of emptiness." When all enter this emptiness, they do not grasp at the four characteristics of dharmatā; they do not receive, do not attach to, do not think about, and do not discriminate new, old, internal, or external, and so forth. If the mind is without reliance, seeing the true Buddha-nature through non-seeing, and abiding in great nirvāṇa through non-abiding phenomena, this is called the "liberation gate of signlessness." This great nirvāṇa is neither cultivated nor produced: not from self, so not cause; not from other, so not condition; not from both, so not combination; not without cause, so not separation; without cultivation and without attainment, it is called the "liberation gate of wishlessness."