四分律刪繁補闕行事鈔 3.424

3.424

三明尼須結界。有人不立比法。然此一法，二眾同秉，各有別眾；非界無以攝人，非界無以羯磨。若不信須結，但僧獨作，應成；事則不爾，故知須結，審委無疑。應自然界，尼僧盡集，唱相結之；本法尼者，且置自然界外；下二眾，同住無妨。又如尼懺僧殘，二眾各結，受隨俱同也。此結界法，佛法東流，行事者用之，有不立者少；然中國僧來傳法，通有賢聖，不共非奪。

Third, explaining that nuns must demarcate a boundary. Some do not establish this practice. However, this single ritual is administered jointly by the two assemblies, each having its own separate gathering; without a boundary there is no way to assemble the persons, and without a boundary there is no way to carry out the karman. If one does not believe it must be demarcated, then if the bhikṣus alone performed it, it should be valid; yet in fact this is not so, hence we know it must be demarcated, thoroughly and beyond doubt. Within the natural boundary, the bhikṣuṇī-saṃgha should assemble entirely, proclaim the markers, and demarcate it; the nuns who underwent the fundamental procedure should temporarily remain outside the natural boundary; the lower two assemblies staying together poses no obstacle. Furthermore, just as when a nun repents a saṃghāvaśeṣa, each of the two assemblies demarcates its own boundary, and the reception and subsequent practices are both identical. As for this method of demarcating boundaries, since the eastward transmission of the Buddhadharma, practitioners have used it, and those who do not establish it are few; furthermore, when monks from India came to transmit the Dharma, including both worthy and noble ones, they did not reject or dispute it.