妙法蓮華經玄義 4.11

4.11

修相者，知息入知息出者，此代數息，調息綿細，一心隨息，入時知從鼻至臍，出時知從臍至鼻，隨照不亂。知風、喘、氣為麁；知息為細。入麁即調令細，如守門人，知入知出，惡遮好進。澁滑、輕重、冷煖、久近、難易皆知。知息為命所依，一息不還即便命盡。覺息與命危脆無常，不生愛慢。知息非我，即不生見。若知息長短，對欲界定；知息遍身，對未到地。除諸身行，對初禪覺觀支；受喜對喜支；受樂對樂支；受諸心行對一心支。心作喜，即喜俱禪；心作攝，即二禪一心支。心作解脫，即三禪樂。觀無常，即四禪不動。觀出散，即空處。觀離欲，即識處。觀滅，即對無所有處。觀棄捨，對非想非非想處。觀棄捨時，即便獲得三乘涅槃。若橫論觀慧，即對四念處（云云）。

As for the practice of the characteristics: "knowing breath in, knowing breath out" substitutes for counting the breath. One regulates the breath so that it is continuous and fine, single-mindedly following the breath: when it enters, knowing it goes from the nose to the navel; when it exits, knowing it goes from the navel to the nose; following and illuminating without distraction. One knows wind, panting, and gasping as coarse, and knows breath as fine. When coarse enters, one regulates it to make it fine—just like a gatekeeper who knows who enters and who exits, barring the bad and letting the good advance. One knows all [aspects]: whether it is rough or smooth, light or heavy, cold or warm, lasting or brief, difficult or easy. One knows that breath is that upon which life depends; if one breath does not return, life forthwith ends. Perceiving breath and life to be fragile and impermanent, one generates neither craving nor arrogance. Knowing breath to be non-self, views do not arise. Knowing whether breath is long or short corresponds to the concentration of the desire realm; knowing breath throughout the whole body corresponds to the intermediate stage; eliminating all bodily formations corresponds to the factors of applied thought and sustained thought in the first dhyāna; experiencing joy corresponds to the factor of joy; experiencing bliss corresponds to the factor of bliss; experiencing all mental formations corresponds to the factor of one-pointedness of mind. The mind generating joy is dhyāna conjoined with joy; the mind concentrating is the factor of one-pointedness of mind in the second dhyāna. The mind attaining liberation is the bliss of the third dhyāna. Contemplating impermanence is the unshakeable fourth dhyāna. Contemplating dispersion is the sphere of boundless space. Contemplating freedom from desire is the sphere of boundless consciousness. Contemplating cessation corresponds to the sphere of nothingness. Contemplating abandonment corresponds to the sphere of neither perception nor non-perception. When contemplating abandonment, one forthwith attains the nirvāṇa of the three vehicles. If discussed horizontally in terms of contemplative wisdom, it corresponds to the four stations of mindfulness (and so forth).