This poem comes from Bai Juyi's Early Departure and Late Return in the Tang Dynasty. It is an out-and-out neighborhood Committee: I don't see the sun in the morning, and I often accompany the west window of the moon at night. Get up early or go out with wine, and come back late to see flowers. If you sit for a long time, ask yourself about Tokyo.
The meaning of this poem is: when I left in the morning, the sun had not yet risen, and when I came back in the evening, the moon was already shining high on the window.