Liu Xizai directly interpreted the softness in Cai Yong's "Soft Pen Makes Amazing Achievements" as a combination of rigidity and softness to illustrate the occurrence of amazing achievements (this is the first case he saw): "Cai Zhong Lang Yun:' Soft pen makes amazing achievements'. I press the word "soft", which is unique but wrong. The cover can be soft and rigid, and soft and rigid are soft. " (62) Actually, Liu Xizai misunderstood here. The characteristic of "combining rigidity with softness" is not softness, but the rigidity and softness in the author's heart: the rigid one gives birth to bones, while the soft one gives birth to tendons; Only by combining rigidity and softness can we have the beauty of plump bones and moist skin. In addition, the spine character is interpreted as the key to calligraphy, and it is considered that the spine character is the key to calligraphy. Those with backbone say that the hole is here, with a hole in the middle and a hole on the side. If the hole is big, the density of words is good, otherwise it is all sick. "