法苑珠林 94.37

94.37

又毘尼母經云。諸比丘住處房前。閑處小便污地。臭氣皆不可行。佛聞之告諸比丘。從今已去不聽諸比丘僧伽藍處處小行。當聚一屏猥處。若瓦瓶若木筩。埋地中就中小便已。以物蓋頭。莫令至臭氣。

Furthermore, the Vinayamātṛkā says: "In front of the rooms where the monks resided, they urinated in quiet spots and soiled the ground; the stench made it completely impossible to walk there. When the Buddha heard of this, he addressed the monks: 'From this day forward, I do not permit the monks to urinate all over the saṃghārāma. You must gather in a secluded, coarse place, bury an earthenware jar or wooden tub in the ground, and urinate into it; when finished, cover the top with an object so as not to let the foul odor escape.'"