摩訶止觀 9.25

9.25

初從麁住，訖至非想，通有四分：退、護、住、進。退分又二：一、任運退，二、緣觸退。緣有內外，外諸方便二十五種吐納失所，是為「外緣觸退」；於靜心中三障四魔而生憂愛，是名「內緣觸退」。後或更修得，或修不得，此人甚多。護分者，善以內外方便，將護定心不令損失。住分者，或因守護安隱不失，或任運自住，即是住分。進分者，或任運進，或勤策進，各有橫竪；橫竪各有漸頓。若十二門一一而進，是名「漸進」；若一時具足，是名「頓進」。特勝、通明，品品而發，是名「橫漸」；一時俱發，是名「橫頓」。又於四分，分分皆有四分，具如《修證》中說（云云）。

From initial coarse abiding up to [the sphere of] neither perception nor non-perception, there are four divisions throughout: retrogression, protection, abiding, and progression. The division of retrogression also has two kinds: first, natural retrogression; second, retrogression from contact with conditions. Conditions are internal and external: when the various external expedients, the twenty-five kinds, cause respiration to lose its balance, this is 'retrogression from contact with external conditions'; when, amidst a quiet mind, anxiety and attachment arise toward the three obstacles and four māras, this is called 'retrogression from contact with internal conditions.' Afterwards, some may cultivate and regain it, while others cannot; such people are very numerous. As for the division of protection: skillfully using internal and external expedients, one cares for and protects the concentrated mind so that it does not suffer loss. As for the division of abiding: whether resting securely without loss due to guarding, or naturally abiding of itself, this is the division of abiding. As for the division of progression: whether progressing naturally or progressing through diligent effort, each has horizontal and vertical aspects; and horizontal and vertical each have gradual and sudden aspects. If one progresses through the twelve gateways one by one, this is called 'gradual progression'; if they are fulfilled all at once, this is called 'sudden progression.' When the superior excellences and thorough illuminations arise rank by rank, this is called 'horizontal gradual'; when they arise all at once, this is called 'horizontal sudden.' Furthermore, within the four divisions, each and every division has the four divisions, fully as explained in the Xiuzheng (and so forth).