妙法蓮華經玄義 9.35

9.35

六、善識道品者，觀生死即涅槃，十界生死色陰皆非淨非不淨，乃至識陰非常非不常。能破八顛倒，即法性四念處，念處中具道品、三解脫及一切法。又知涅槃即生死，顯四枯樹；知生死即涅槃，顯四榮樹；知生死涅槃不二，即一實諦，非枯非榮，住大涅槃也。

Sixth, skillfully discerning the aids to the path: Contemplating birth and death as identical to nirvāṇa, the form aggregate of birth and death across the ten realms is neither pure nor impure, up through the consciousness aggregate being neither permanent nor impermanent. Being able to break through the eight inversions is the four applications of mindfulness of dharma-nature; within these applications of mindfulness are replete the aids to the path, the three liberations, and all dharmas. Furthermore, knowing that nirvāṇa is itself birth and death reveals the four withered trees; knowing that birth and death is itself nirvāṇa reveals the four flourishing trees; knowing that birth and death and nirvāṇa are non-dual is the single real truth, neither withered nor flourishing, abiding in the great nirvāṇa.