It’s an illusion: the stable, hard, unchanging permanence of a Rock.
Every movement around the rock leaves a mark on it. The stream of water that flows beneath; the lightest gale that brushes past; the descent of a withering leaf; every speck of dust that touches its face — everything leaves behind it’s mark; subtle but permanent.
The solid, unchanging stillness of the Rock is made of continuous, flowing change. Slow yet deep, imperceptible yet irreversible change.