In the calligraphy of Preface to Lanting, there is a saying that "bamboo grows here in the mountains". Why is the word "Chongshan" written outside?

Because the ancients used the brush as the main writing tool, one was for communication, and the other was not for creating calligraphy works. Therefore, it is inevitable to write casually, and it is also possible to write wrongly and miss words. When Wang Xizhi was writing, he was also very casual. He forgot to write two words at that time. So, in order to make up for it, he had to add these two words outside the format. A few years later, later generations felt that Wang Xizhi's handwriting was very good, even if the manuscript was misspelled and missed, it was a rare calligraphy work. Therefore, this Preface to Lanting Collection has been handed down from generation to generation with the reputation of "the best running script in the world". Its mistakes and omissions are also preserved as part of calligraphy works.