The two characters 玉宇（yu yu）mean Jade House.
The traditional value of jade in China
The Chinese admiration of jade stones goes a long way back.
On the one hand, it looked great and was therefore thought as the perfect gemstone. – Jewellery, belt buckles, ornaments and buttons on clothes and expensive pieces of furniture have been carved out of jade stones for millennia.
On the other hand, jade stones were also thought of as artefacts which were able to provide a connection to the divine. Therefore, jade was also used as a ritual or healing stone.
Jade as imperial stone
The Chinese character 玉 is able to give us another clue concerning the significance of jade. The point stands for the stone itself. The rest of the character (王) – the earth with an added stroke above, which wants to symbolize heaven or the (heavenly) order – means ruler or king. And when everything adds up: Jade is an imperial stone.
The Jade House as House of the Jade Emperor and …
In Chinese mythology the „Jade House“ is the house of the Jade Emperor. The Jade Emperor is the highest or first God and at the same time a legendary ruler. Legend tells us that he ruled until a just order was established, only to retreat thereafter and devote himself to meditation. Strengthened over an everlasting period of time, he came back and saved the world from evil demons. Which house would be the right house for such a great and wise ruler? Certainly a very big and beautiful one, which is able to appropriately express his dignity. So, which house is the biggest you could think of? – Very true! And That is why the characters for Jade House also mean universe.
Poem
Ning devoted this poem to the character 玉宇:
Video Calligraphy 玉宇
Calligraphy: Wang Ning
