The Middle-Length Āgama 98.17

98.17

「復次，比丘觀身如身，比丘者，如本見息道骸骨青色，爛腐食半，骨璅在地，見已自比：『今我此身亦復如是，俱有此法，終不得離。』如是比丘觀內身如身，觀外身如身，立念在身，有知有見，有明有達，是謂比丘觀身如身。復次，比丘觀身如身，比丘者，如本見息道離皮肉血，唯筋相連，見已自比：『今我此身亦復如是，俱有此法，終不得離。』如是比丘觀內身如身，觀外身如身，立念在身，有知有見，有明有達，是謂比丘觀身如身。

“Furthermore, a monk observes the body as body. That monk sees as before a skeleton that’s bluish, rotted, half-eaten, or just bones on the ground at a charnel ground. He compares himself to what he’s seen: ‘Now, this body of mine will be likewise. Both have this principle; it’ll never escape this.’

“Thus, a monk observes the internal body as body and observes the external body as body. He establishes mindfulness in body with knowing, seeing, insight, and comprehension. This is called a monk observing body as body.

35. “Furthermore, a monk observes body as body. That monk as before sees skin, flesh, and blood removed [from the bones] with only sinews connecting them at a charnel ground. He compares himself to what he’s seen: ‘Now, this body of mine will be likewise. Both have this principle; it’ll never escape this.’

“Thus, a monk observes the internal body as body and observes the external body as body. He establishes mindfulness in body with knowing, seeing, insight, and comprehension. This is called a monk observing body as body.