The concept of “male left, female right” is also reflected in the choice of wrist for taking one’s pulse in Chinese traditional medicine. In terms of temperament, male is masculine, belonging to yang-the left, while female is gentle and soft, belonging to yin-the right. The yang was firm and strong, and the yin was soft and weak. Ancient people classified things that were big, long, up, and left as yang, and things that were small, short, down, and right as yin. For example, everything could be differentiated by size, length, up or down, left or right, etc. In the traditional concept, the two opposite sides in everything were yin and yang. This custom was also closely associated with the philosophy of the ancient people. This was the origin of the Chinese traditional custom of “male left, female right.” The Sun God was Pangu’s left eye, and the Moon God was Pangu’s right eye. The book “Wu Yun Nian Li Ji,” written by Xu Zheng during the Three Kingdoms period, states that the sun and the moon of the Chinese nation were transformed from the two eyes of Pangu. How did this custom come into being? As the legend goes, after the ancestor of the Chinese people, Pangu, became a deity, his body parts and organs turned into the sun, the moon, stars, mountains, rivers, lakes, all things on earth, and all lives. In China, the custom of considering the left side as male and the right side as female seems to have permeated all aspects of people’s daily lives.