維摩經玄疏 6.51

6.51

First, briefly discerning the characteristics of the four gates: "gate" takes leading through as its meaning; the correct fourfold proposition expounded by the Buddhist teaching can lead practitioners through to the substance of the true nature and true mark, and is therefore called a gate. If outsiders speak of the four propositions based on heterodox causes and conditions or no causes and conditions, they each see the principle of four kinds of heterodox dharmas through these four propositions, generating from them the fourteen unanswerable questions and sixty-two views, giving rise to all defilements and karmas, and sinking into the cycle of birth and death. These are the four gates of the heterodox path, which will not be described here. The four gates of the Buddhadharma are the four propositions of correct causes and conditions, which can lead practitioners through so that they enter the nirvāṇa of the supreme meaning together. Hence the Dazhidulun states: "Four gates enter the cool pool," and also compares: "Prajñā is like a great mass of fire, impossible to grasp on four sides," and also states: "Prajñāpāramitā has four kinds of characteristics, which are the meaning of the four gates." Looking respectfully into the Buddhadharma, since there is the difference of four teachings, now in clarifying the gates with reference to the teachings, there are four distinctions each: first, the four gates of the Tripiṭaka; second, the four gates of the shared teaching; third, the four gates of the distinctive teaching; fourth, the four gates of the perfect teaching.