摩訶止觀 6.205

6.205

復次，行人依無生門修四三昧，或時歡喜頂受，或信善心生，或惡覺執破，或恍恍欲悟。若爾者，此無生門是其道門；若不爾，非其門也。當更從無滅門入，喜生、善發、執破、近道，當知無滅是其道門；不爾，於其非門。如是廣歷眾門一一檢試，會有相應。張羅既廣，心鳥自獲。為是義故，將橫約竪，以顯門通也。

Furthermore, when a practitioner relies on the gate of non-arising to cultivate the four samādhis, at times joy arises and they receive it with reverence, or wholesome thoughts of faith arise, or evil awareness and grasping are broken, or they feel in a daze as if on the verge of awakening. If so, this gate of non-arising is their gate to the Path; if not, it is not their gate. They should instead enter from the gate of non-ceasing: if joy arises, wholesomeness is brought forth, grasping is broken, and they draw near to the Path, know that non-ceasing is their gate to the Path; if not, it is not a gate for them. Widely going through the multitude of gates and testing them one by one in this way, there will surely be one that accords. When the net is spread wide, the bird of the mind is naturally caught. For this reason, the horizontal is correlated with the vertical to reveal the penetrative reach of the gates.