坐禪三昧經 1.9

1.9

婬欲多人習不淨觀，從足至髮不淨充滿，髮毛爪齒、薄皮厚皮、血肉筋脈、骨髓肝肺、心脾腎胃、大腸小腸、屎尿洟唾、汗淚垢坋、膿腦胞膽、水微膚、脂肪腦膜，身中如是種種不淨。復次不淨觀者：觀青瘀膖脹、破爛血流、塗漫臭膿、噉食不盡、骨散燒焦，是謂不淨觀。

Those with an excess of lust should practice the contemplation of impurity. From the feet to the hair, it is filled with impurity: hair of the head, hair of the body, nails, teeth, epidermis, dermis, blood, flesh, sinews, vessels, bone marrow, liver, lungs, heart, spleen, kidneys, stomach, large intestine, small intestine, feces, urine, snot, spittle, sweat, tears, grime, pus, brain, bladder, bile, serum, subcutaneous fat, and cranial membranes. Within the body there are various impurities such as these. Furthermore, regarding the contemplation of impurity: one contemplates the bluish-bruised, the bloated and distended, the ruptured and bleeding, smeared with foul pus, incompletely devoured [by beasts], scattered bones, and charred ashes. This is called the contemplation of impurity.