Shundo David Haye – Zen Priest

‘“Trees and rocks,” alludes to the story of the Buddha’s past life recorded in the Mahāparinirvāṇa-sūtra. When he was the “Child of the Himalayas” pursuing the truth in the mountains, a demon told him the first two lines of a four-line poem: 

“Actions are without constancy;
Concrete existence is the arising and passing of dharmas.” 

The demon said it was too hungry to tell the child the last two lines, so the child offered his own body as a meal for the demon if it would recite the last two lines. So the demon recited the last two lines:

 “After arising and passing have ceased,
The stillness is pleasure itself.”

The child preserved the verse for posterity by writing it on some nearby trees and rocks in his own blood, before being eaten by the demon.’ (Shobogenzo Kesa Kudoku, Nishijima-Cross translation, footnote)