wéi biān sān jué 韦编三绝
Leather Thongs Binding Wooden Strips Breaking Three Times
In ancient China, people recorded events by writing on bamboo or wooden strips. They used boiled leather thongs threaded through little holes made on those strips to bind them together into a book according to a certain order. According to the Records of the Historian, Confucius avidly read The Book of Changes in his old age. He used the book so often that the leather thongs binding the wooden strips broke three times. Later on, this term is used to describe a person who reads diligently.
In his old age Confucius loved to study The Book of Changes… He used this book so much that the leather thongs binding the wooden strips wore out three times. (Sima Qian: Records of the Historian)