  The Daodejing is also referred to as the Daode zhenjing (True Classic of the Way and Virtue), the Taishang xuanyuan daodejing (Classic of the Way and Virtue of the Highest Profound Origins), and less formally the “five-thousand character” text, on account of its approximate length. Most versions exceed five thousand characters by about five to ten percent, but it is interesting to note that numerological considerations later became an integral part of the history of the work. According to the seventh-century Daoist master Cheng Xuanying, it was Ge Xuan (fl. 200 C.E.), a revered Daoist adept, who shortened the Laozi text that accompanied the Heshanggong commentary to fit the magical number of five thousand. This claim cannot be verified, but a number of Laozi manuscripts discovered at Dunhuang contain 4,999 characters.