四分律刪補隨機羯磨 1.166

1.166

(At that time, when bhikṣus had matters requiring a four-person saṃgha karman arise, or matters requiring a five-person, ten-person, or twenty-person saṃgha karman arise, the great assembly among them was exhausted by assembling. The Buddha said: "I allow [you] to bind a platform for precepts, proclaiming the boundary markers of the four directions—whether by setting stakes, stones, or marked borders, establishing the demarcations." The Vinayamātṛkā states: "It must be surrounded by a mahāsīmā." Vinayas such as the Mahīśāsaka state that it must be bound before the mahāsīmā. If one wishes to make it, first set three tiers of boundary markers: the inner tier is called the outer markers of the platform for precepts; the middle tier is called the inner markers of the mahāsīmā; the outermost tier is called the outer markers of the mahāsīmā. After all three markers are set, the bhikṣus within the natural boundary assemble, and inside the markers of the platform for precepts, first have one bhikṣu proclaim the outer markers of the platform for precepts, who should speak thus:)