坐禪三昧經 2.53

2.53

行菩薩道者，於三毒中若婬欲偏多，先自觀身：骨肉皮膚、筋脈流血，肝肺腸胃、屎尿涕唾，三十六物、九想不淨，專心內觀不令外念；外念諸緣，攝之令還。如人執燭入雜穀倉，種種分別豆、麥、黍、粟無不識知。復次觀身六分：堅為地分、濕為水分、熱為火分、動為風分、孔為空分、知為識分。亦如屠牛，分為六分，身首四支，各自異處。身有九孔，常流不淨，革囊盛屎，常作是觀，不令外念；外念諸緣，攝之令還。若得一心，意生厭患，求離此身，欲令速滅，早入涅槃。是時當發大慈大悲，以大功德，拔濟眾生，興前三願：「以諸眾生，不知不淨，起諸罪垢，我當拔置於甘露地。復次，欲界眾生樂著不淨如狗食糞，我當度脫至清淨道。復次，我當學求諸法實相，不有常不無常、非淨非不淨，我當云何著此不淨？觀不淨智從因緣生，如我法者當求實相，云何厭患身中不淨而取涅槃？當如大象度駛流水窮盡源底，得實法相滅入涅槃，豈可如獼猴諸兔畏怖駛流趣自度身？我今當學如菩薩法，行不淨觀除却婬欲，廣化眾生令離欲患，不為不淨觀所厭沒。」

One who practices the bodhisattva path, if lust is predominant among the three poisons, should first contemplate his own body: bones, flesh, skin, tendons, veins, flowing blood, liver, lungs, intestines, stomach, feces, urine, snot, and spit—the thirty-six substances and the nine contemplations of impurity, focusing the mind on internal contemplation without allowing external thoughts; external thoughts of various objects are gathered and brought back. It is like a person holding a lamp and entering a granary of mixed grains, distinguishing beans, wheat, panicled millet, and foxtail millet, leaving none unrecognized. Furthermore, contemplate the six constituents of the body: hardness is the earth constituent, moisture is the water constituent, warmth is the fire constituent, movement is the wind constituent, cavities are the space constituent, and knowing is the consciousness constituent. It is also like butchering an ox and dividing it into six parts: torso, head, and four limbs, each in a different place. The body has nine apertures, constantly discharging impurity, a leather bag containing feces. Constantly perform this contemplation without allowing external thoughts; external thoughts of various objects are gathered and brought back. If one-pointedness of mind is attained, a feeling of disgust and weariness arises in the mind, seeking to be free of this body, wishing to make it quickly cease and to enter nirvāṇa early. At that time, one should give rise to great friendliness and great compassion, and with great merit rescue sentient beings, bringing forth the former three vows: 'Because sentient beings do not know impurity and give rise to sins and defilements, I shall raise them up and place them in the ground of amṛta. Furthermore, sentient beings of the desire realm delight in clinging to impurity like dogs eating dung; I shall deliver them to the pure path. Furthermore, I should learn to seek the true mark of dharmas: neither permanent nor impermanent, neither pure nor impure. How could I cling to this impurity? The wisdom that contemplates impurity arises from causes and conditions. One who follows my Dharma should seek the true mark; how could I be disgusted by the impurities in the body and seize nirvāṇa? I should be like a great elephant crossing a swift current, reaching the very bottom of the source, realizing the true mark of dharmas and ceasing into nirvāṇa; how could I be like monkeys and hares who fear the swift current and hasten only to cross for their own bodies? I should now train according to the bodhisattva's dharma, practicing the contemplation of impurity to eliminate lust, widely converting sentient beings to make them leave the affliction of desire, without being submerged in disgust by the contemplation of impurity.'