Er Ya was written between the Warring States Period or the Han Dynasty, and the upper limit should not be earlier than the Warring States Period, because some materials used in the book came from books such as Chu Ci, Zhuangzi and Lv Chunqiu.
The academic value of Er Ya;
Today, Erya still has high academic value, and it is multifaceted. As the earliest existing dictionary in China, Erya has collected and explained a large number of pre-Qin words, preserved rich dialect materials, and included various social and natural terms, so it is not only a Chinese dictionary, but also an encyclopedia.
Someone in the Song Dynasty said: "If you want to learn from the ancients, you must first understand Er Ya, and then the words of hundred schools of thought in the six countries can be sought after." Erya is still an indispensable reference book for us to read and study ancient books.