The philosophy at the water's edge is not giving up day and night, while the philosophy in the mountains is not knowing the sun and the moon. How do you understand this sentence of Yu?

I think the first sentence should be influenced by Confucius' sentence "The deceased is like a husband, not giving up day and night"; The edge of water is a place, the mountain is a substance, and the sun and the moon imply time. "The mountains don't know the sun and the moon." In other words, the mountain doesn't know the passage of time, and it remains unchanged, that is, it has reached a state of selflessness. These two sentences are related to time. The first sentence is lamenting the passage of time, and the second sentence is completely unaware of the existence of time. Obviously, the realm of the second sentence is much higher than that of the first sentence.