四分律刪繁補闕行事鈔 1.267

1.267

問：界標與相及體，若為分之？答：標謂山石之物，用為指的；相即標畔，界體之外表也；體謂相內作法之所。或標即體，或標異體；相必體外。臨時處分，三所不同，並預委也。

Question: How does one distinguish among the boundary marker (biāo), the boundary mark (xiāng), and the substance of the sīmā (tǐ)? Answer: The marker refers to an object like a mountain or stone used as a reference point. The boundary mark is the perimeter of the marker, the outer surface of the substance of the sīmā. The substance of the sīmā refers to the place within the boundary marks where the rite is performed. In some cases the marker is the substance itself; in some cases the marker is distinct from the substance; the boundary mark is necessarily external to the substance. When executing it at the time, these three loci differ, and all must be understood in advance.