四部律并論要用抄 2.48

2.48

與未受具戒人同宿戒　得二夜三夜當護明相。第四宿初夜隨脇著地犯　僧祇云。第四宿當別房。若露地天雨寒雪聽入房坐。至地了不得臥。若老病不堪久坐。聽以縵障。若齊頂。若齊腋下垂地。當用緻物作。不得容猫子過得臥也。若更互坐至曉不犯。

The precept against lodging together with a person not fully ordained: One is permitted two nights; on the third night, one must guard the appearance of dawn. In the initial watch of the fourth night, an offense is incurred as soon as one's ribs touch the ground. The Mahāsāṃghika[-vinaya] states: "On the fourth night, one should use separate rooms. If out in the open and it rains or is bitterly cold with snow, they are permitted to enter a room and sit; until dawn they must not lie down. If someone is old or ill and cannot endure prolonged sitting, they are permitted to use a cloth screen. Whether level with the crown of the head or level with the armpits, it should hang to the ground and must be made of dense fabric, not allowing a kitten to pass through, then they may lie down. If they take turns sitting until dawn, there is no offense."