四分律行事鈔資持記 2.637

2.637

《善見》中，初引論文。樹取影覆，隨時大小；林無限齊，故約肘量。十四肘計二丈五尺二寸，得四步餘尺二。人來往者，謂有礙也。上下，會通律論林相不同。難即是礙。

In the Samantapāsādikā, it first cites the text of the commentary: for a tree, one takes the shadow's coverage, which varies in size with the time [of day]; groves have no fixed limit, so it is determined by cubit-measurements. Fourteen cubits equals two zhàng, five chǐ, two cùn, yielding four paces and remaining one chǐ, two cùn. "People passing back and forth" means that there is an obstruction. "Above and below" synthesizes the differences in the grove's marks between the Vinaya and the commentary. A difficulty is precisely an obstruction.