This sentence came from a passage in 'Dream of the Red Chamber'. The author was from the Qing Dynasty. The original text was: "When the forest is exhausted, there will be a mountain." The mountain had a small mouth, as if there was light. Those who enter from the mouth go up the steps. If you don't go up, you will become a mountain peak. Because the ridge has become a forest under it." A water source appeared at the end of the forest, and a mountain appeared. This mountain had a small opening that seemed to have light inside. Enter through this small opening and climb up the stairs. If he didn't go up, it would be a peak because this peak had become a mountain. This was because there was a forest below the ridge.