摩訶止觀 5.182

5.182

經釋「不生不生」者：「不生不生，名大涅槃。」生相盡故，修道得故。今解：果由因剋，故言「修道得故」。斷德已圓，無明不生；智德已圓，般若不生，故言「不生不生」。此說自行寂滅忍，果義成也。因果既圓，即如《佛藏》所明一吹唾即滅即立，是其義焉。

The sūtra explains "non-arising non-arising": "Non-arising non-arising is called great nirvāṇa." This is because the characteristics of arising are exhausted, and because it is attained through cultivating the path. It is now explained: the fruit is secured through the cause, hence it says "because it is attained through cultivating the path." The virtue of eradication is fully perfected, so avidyā does not arise; the virtue of wisdom is fully perfected, so prajñā does not arise; therefore it is called "non-arising non-arising." This speaks of the endurance of quiescence and cessation in one's own practice, in which the meaning of the fruit is accomplished. Since cause and effect are both fully perfected, this is just as the Fo zang [jing] explains: with a single blow and a spit, there is instant destruction and instant establishment—this is its meaning.