Help me find a poem containing the words Yu and Xuan, which can be connected together, but in one sentence.

"Yueyang Tower Don't Fight Four Zhi" Han Yu Dongting Kyushu, who is the greatest, and let Nanhui Group cliff flow, how bold and unrestrained in the north. Store 700 Li and swallow all kinds of strange shapes. Since ancient times, it has been unclear and does not return to the ring. The wind is stirring day by day, and the strange things are long. Set off an uproar, the universe is small and there are many obstacles. Towering flowers pull out, Teng is stronger. ...