"Falling flowers and flowing water, spring has gone, and the world is in heaven and earth." It means that like the lost river water and the fallen red flowers, they go back together with spring. Comparing the past and present, one is heaven and the other is earth.
The poem comes from "Langtaosha·Nostalgia" written by the Southern Tang Dynasty monarch Li Yu. The full text is:
The rain outside the curtain is gurgling, and the spring is fading.
Luo quilt cannot bear the cold at dawn.
In the dream, I didn’t know that I was a guest, and I was greedy for pleasure for a while.
Don’t lean on the fence alone, the world is unlimited.
It is easy to say goodbye but hard to see.
Flowing water and falling flowers, spring is gone, heaven and earth are gone.
This poem was written when the author was taken to Bianjing under house arrest after he surrendered to the Song Dynasty. The word "go" in the last sentence contains so much nostalgia, regret, sorrow and vicissitudes of life. "Heaven and Earth" alludes to the two completely different life experiences of the monarch in the past and the prisoner today. The whole poem expresses the author's endless longing for his motherland, home and the beautiful life in the past.