Ekottaragama (Sanskrit fragments) 12.1.10

12.1.10

「復次，比丘！觀此身有諸孔，漏出不淨。猶如彼人觀竹園，若觀葦叢。如是，比丘觀此身有諸孔，漏出諸不淨。

“Furthermore, a monk contemplates this body as having orifices from which impurities flow. He does so like someone viewing a bamboo park or looking at a stand of reeds. In this way, the monk contemplates this body as having orifices from which impurities flow.