80.天地之道恒久而不已——出自《恒·彖》
今譯：天地間的自然規律是永遠不停地變化。
衍言：不固步自封，永遠站在時代潮流的前沿去爭取前途。
《周易》小詞典：《恒》卦巽下震上，為雷動風應象，為天地間最常見的現象，彖辭即取其義。
The way of heaven and earth is to be long continued in their operation without stopping.——- from The Tuan, Heng
Modern interpretation: The law of nature indicates that the world is always changing.
Moral: We should not stand still and refuse to make progress. On the contrary, everybody should follow closely the trend of the times and strive for a better prospect.
Glossary: With the trigram Xun below and the trigram Zhen above, the Hexagram Heng presents the images of thunder and wind in mutual communication, which is a common natural phenomenon as signified in the Tuan.