"There are mulberries in the south mountains and poplars in the north mountains" comes from "The Book of Songs: There is a Terrace in the Nanshan Mountains".
Original poem:
There is a platform in the south mountain, and a terrace in the north mountain. Joy is only a gentleman's, the foundation of a country. A happy gentleman will live forever.
There are mulberries in the southern mountains and poplars in the northern mountains. A happy gentleman is the light of the country. A happy gentleman will live forever.
Translation:
Sodium rosea grows in the southern mountains, while pigweed grows in the northern mountains. A gentleman is happy and lays the foundation for his country. A gentleman is so happy that he will live forever.
Green mulberries grow in the southern mountains, while white poplars grow in the northern mountains. A gentleman is happy and strives for glory for his country. A gentleman is really happy and has a long life.
Appreciation of the poem "There is a Terrace in Nanshan"
Zhu Xi believes that this poem "is also a common joy of Yanxia", which can be followed. It should be a poem to praise the ruler's virtues and celebrate his birthday. ***Five chapters, six sentences each. The first two sentences of each chapter are all metaphorical. Zheng Xuan's notes said: "When the mountains are prosperous, they are covered with grass and trees, making them tall. It is a metaphor for a ruler to have virtuous ministers to show his self-respect." This is quite the purpose of the poem.
The last four sentences of each chapter are all words of praise and birthday wishes. Only the last chapter "Paul Aier's Queen" is to wish her successors. This kind of poem to congratulate the superior is the first of its kind in later generations.