四分律刪繁補闕行事鈔 2.128

2.128

三樹界者。與人等，足蔭覆如趺坐（如此樹相已上，乃有衣界可護也）；此但明其小相。《十誦》：不相接樹，取日正中時陰影覆處，若雨墮時水不及處；置衣在此樹，身在餘處，若不取衣等皆犯。若相接樹，乃至一拘盧舍者，隨所著衣無犯。《善見》日正中時，影覆處同上；若樹枝偏長，衣在陰頭，人在樹根，亦不失衣。林界者，衣在林中，十四肘中不失衣；此林有人來往，無衣界，應隨身，不隨者失。上《十誦》林界一拘盧者，謂是大林無難；此言十四肘者，謂四樹相連，勢非廣及，故衣界狹小也。《僧祇》：蒲萄蔓架，一切瓜瓠等架，各四相取二十五肘，名衣界。《明了論》解：若衣在樓樹下，身在上者，失衣；若衣在上，身在樓樹下，不失，以上得落下故。

Third, the tree boundary: equal in height to a person, its shade sufficient to cover one sitting cross-legged (only with a tree mark like this or larger does a robe boundary exist to be protected); this merely clarifies its minimal mark. The Daśādhyāya-vinaya: 'For trees that do not connect, one takes the area covered by the shadow at midday, or the place that rainwater does not reach when rain falls; if one places the robe under this tree while one's body is elsewhere, failing to retrieve the robe and so forth all constitute an offense. If the trees connect, up to one krośa, there is no offense wherever the robe is placed.' The Samantapāsādikā states that the area covered by shade at midday is the same as above; if a tree branch is exceptionally long, and the robe is at the tip of the shade while the person is at the tree trunk, one also does not lose the robe. Regarding the forest boundary: if the robe is in the forest, one does not lose the robe within fourteen cubits; if people come and go in this forest, there is no robe boundary, and it should follow one's person; if it does not follow, it is lost. The one krośa for the forest boundary in the Daśādhyāya-vinaya above refers to a great forest without danger; the fourteen cubits mentioned here refers to four trees connected together whose extent is not vast, and thus the robe boundary is narrow and small. The Mahāsāṃghika-vinaya: 'For grape trellises and all melon and gourd trellises, each takes twenty-five cubits on all four sides, which is called a robe boundary.' The Vinayavibhāṣā explains: 'If the robe is beneath a tree near a tower while one's body is above, one loses the robe; if the robe is above while one's body is beneath the tower tree, one does not lose it, because from above one can drop it down.'