摩訶止觀 6.63

6.63

次、通教四門不同者：若明一切假、實從無明生，無明如幻，所生一切亦皆如幻。如幻雖如虛空，而有如幻破假之觀。雖如虛空而如虛空生，故云：「諸法不生而般若生。」如是觀慧能破諸見、諸思，成惑智、因果等不生，是名有門觀意也。

Next, regarding how the four gates of the shared teaching differ: if one explains that all provisional and real [dharmas] arise from avidyā, and avidyā is like an illusion, then all that it produces is also like an illusion. Although being like an illusion is like empty space, there is a contemplation that breaks the provisional like an illusion. Although like empty space, it arises like empty space; hence it is said: "Dharmas do not arise, yet prajñā arises." Contemplative wisdom such as this can break views and thoughts, bringing about the non-arising of delusion, wisdom, cause, effect, and so forth; this is called the purpose of the contemplation of the existence gate.