摩訶止觀 9.6

9.6

此十門與五門、十五門，云何同異？但有開合之異耳。開五為十者：開數息出特勝、通明；開不淨出背捨、大不淨；慈心、因緣守本；念佛門，《毘曇》名界方便，《禪經》稱念佛，此亦守本；神通約九禪上發，不專據一法。合十五門為十者：數息、不淨各有三，則不合。慈心有三，但合為一，即眾生慈也。沒二名者，禪是門戶詮次事法，法緣是二乘入理觀，無緣是大乘入理觀，沒理去二，存事唯一。若開者，即屬二乘、菩薩兩境中攝。因緣亦三門，三世輪轉麁，果報、一念明義細，細故附理，麁故屬事；今沒細存麁，但稱三世門也。念佛亦三，但取念應佛耳。神通但取五通。若但取五門，有所不收；若取十五，義濫於理，是故簡理開事。雖開合不同，各有其意。

How are these ten gates the same as or different from the five gates and fifteen gates? There is only the difference of expansion and contraction. Expanding the five into ten: expanding breath counting brings forth the superior excellences and total brightness; expanding impurity brings forth the liberations and the great impurity; loving-kindness and causes and conditions keep to the original; the gate of mindfulness of the Buddha is named dhātu-upāya in the Abhidharma and called mindfulness of the Buddha in the Dhyāna-sūtra, and this also keeps to the original; supernatural powers arise on the basis of the nine dhyānas, not relying exclusively on a single dharma. Combining the fifteen gates into ten: breath counting and impurity each have three, which are not combined. Loving-kindness has three, but is combined into one, namely loving-kindness toward sentient beings. Dropping the two names is because dhyāna is an sequential phenomenal dharma for entering; conditions of dharmas is contemplation entering the principle for the two vehicles, and unconditioned is contemplation entering the principle for the Mahāyāna; dropping the principle and removing the two, only the phenomenal remains as one. If expanded, they are subsumed under the two realms of the two vehicles and bodhisattvas. Causes and conditions also has three gates: the transmigration through the three times is coarse, while retribution and a single thought-moment explain the meaning subtly; being subtle, they align with the principle, and being coarse, they belong to phenomena; now dropping the subtle and preserving the coarse, it is called only the gate of the three times. Mindfulness of the Buddha also has three, but here takes only mindfulness of the response Buddha. Supernatural powers takes only the five supernatural powers. If one takes only five gates, some things are omitted; if one takes fifteen, the meaning is conflated with the principle; therefore, the principle is eliminated and phenomena expanded. Although expansion and contraction differ, each has its purpose.