JhānavibhaṅgaSuttantabhājanīya

Abhidhammapiṭaka · Vibhaṅga · Vol. 35 · Section 617

[617] "The root of a tree" (rukkhamūla): the root of a tree is simply the root of a tree. A mountain is simply a mountain. A gorge is simply a gorge. A mountain cave is simply a mountain cave. A charnel ground (susāna) is simply a charnel ground. The open air is simply the open air. A heap of straw is simply a heap of straw.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.