四分比丘戒本疏 2.10

2.10

第二、離衣宿戒。制戒本意為新受戒人，若更廣張卒尋未曉，曠但且隨身即為未犯，若欲洞曉應求廣聞，今且略之也。「除僧羯磨」者，若身病衣重，有緣須行，從僧三乞。僧作白二，許三衣中隨留一衣。雖逕明相，不犯離衣宿，廣辨如律。作衣持衣等法，不暇廣陳。

Second: the precept against staying overnight separated from one's robes. The original intention of instituting this precept was for newly ordained persons. If explained broadly right away, it would be difficult to comprehend in haste; but if it is always kept on one's person, it does not constitute an offence. If one wishes to comprehend it thoroughly, one should seek broad learning; here it is omitted for brevity. Regarding "except by a saṃgha-karma": if one's body is ill and the robes are heavy, and having cause, one must travel, one makes three requests to the Saṃgha. The Saṃgha performs a ñattidutiya-kamma, permitting one to leave behind whichever one among the three robes. Even if the appearance of dawn passes, one does not commit the offence of staying overnight separated from one's robes; the detailed explanations are as in the Vinaya. As for the procedures for making robes, formally resolving to keep robes (adhiṣṭhāna), and so forth, there is no leisure to set them forth extensively.