Where is the origin of "green hills don't change, green waters don't flow"

From Bai Juyi's poem Parting

Parting: Bai Juyi

In late autumn, the words leave, and the cold wind blows the leaves all over the stream.

I was so generous in my chest that I turned around and burst into tears.

The green hills don't change into flowing water, but the bright moon is still thin.

Forever and ever, there is an end, but this endless sadness is endless.

Translation:

Say goodbye in late autumn, the cold wind blows and the stream is full of fallen leaves.

I was filled with emotion in my chest and turned to say something. My clothes were wet with tears.

The castle peak does not change, the water keeps flowing, the moon remains the same, and the stars are becoming scarce.

Things that last forever sometimes disappear, but this hatred is eternal.

Interpretation of related poems:

The last sentence quotes the last sentence of Bai Juyi's Song of Eternal Sorrow. It is usually said by Jianghu people when they say goodbye, and it has appeared many times in the TV series The Duke Of Mount Deer.

Song of Eternal Sorrow is a long narrative poem by Bai Juyi, a poet in the Tang Dynasty. The whole poem vividly describes the love tragedy between Xuanzong of Tang Dynasty and Yang Guifei. With the help of historical figures and legends, poets have created touching stories and reproduced the truth of real life through their own artistic images, which have infected readers for thousands of years. The theme of this poem is "Song of Eternal Sorrow". This poem has had a far-reaching influence on many literary works in later generations.