律戒本疏 1.81

1.81

二十八共尼屏覆處坐　迦留陀夷往至掘多尼房。屏處坐語。尼眾白佛。因是結戒。欲心狂發。不擇親疎。譏謗之生亦無分別故一切斷也。一坐一墮。若十起十坐十波逸提也。

[Rule] Twenty-eight: Sitting with a nun in a screened and covered place. Kālodayin went to the nun Guptā's room and sat speaking with her in a secluded place; the assembly of nuns informed the Buddha. For this reason, the precept was formulated: When lustful thoughts wildly arise, they do not distinguish between near or distant relatives; the arising of slander also makes no distinction, so it is severed entirely. For sitting once, there is one pāyattika; if getting up ten times and sitting ten times, there are ten pāyattikas.