Yogācārabhūmi-śāstra: Volume 34 (27)

How to observe the nature of change and impermanence in mountain phenomena? At one time, seeing the mountain with luxuriant forests and jagged rocks towering high. Then at another time, seeing that forest and jagged rocks withered, ruined, uneven and irregular, burned by fire or washed away by water. Having seen these things, then thinking thus: Thus all conditioned phenomena, their nature is impermanent. The rest as previously said.

How to observe the nature of change and impermanence in mountains and mountain ranges? At one time, seeing the mountain with flourishing forests, rocks standing densely and towering into the clouds. Then at a later time, seeing the rock-covered forest withered and ruined, on the verge of collapse, uneven and irregular, or burned by fire or washed away by water. After observing these things, then thinking in the heart: Thus all conditioned phenomena, their nature is truly impermanent.