摩訶止觀 9.109

9.109

善知通塞者：達因緣真名「通」；起見思著為「塞」。沈真為不通；達因緣事為不塞。於三道起法愛為塞；達因緣中理名為通。若於番番起無明、愛、取、行、有為失；若於番番悉有智慧名得。或直就有作等四種苦、集論塞；四種道、滅為通。或直就三假故為塞；破三假無生為通。通惑既爾，別惑亦然。或直就四見起十使為塞；破見為通（云云）。

Regarding skillfully knowing the open and the blocked: penetrating the truth of dependent origination is called "open"; generating attachment to views and thoughts is "blocked." Sinking into truth is not open; penetrating the phenomenal facts of dependent origination is not blocked. Giving rise to Dharma-attachment toward the three paths is blocked; penetrating the principle within dependent origination is called open. If in successive turns one gives rise to ignorance, craving, grasping, karmic formations, and existence, that is loss; if in successive turns there is entirely wisdom, that is gain. Or, directly taking the four kinds of suffering and accumulation, such as [those of] deliberate action, as blocked, and the four kinds of path and cessation as open. Or, directly taking the three provisionalities as blocked, and shattering the three provisionalities into non-arising as open. Just as this is so for common delusions, it is likewise for distinctive delusions. Or, directly taking the generation of the ten proclivities from the four views as blocked, and shattering views as open, and so forth.