《水经注·卷十九》
他拿起石头敲了一下梓树，有人回答道：来了！郑容就恍如睡梦中一般，清醒过来时，他看到一座宫阔，样子像是帝王的住所。一个侍者出来了，接过信到里面去了。
应曰：诺。郑容如睡，觉而见宫阙，若王者之居焉。
He picked up the stone and knocked it on the sweetgum tree, and someone answered, "Here!" Zheng Rong suddenly came to his senses as if in a dream. When he woke up, he saw a magnificent palace that looked like it was built by an emperor. A waiter came out and took the letter inside.