《后汉书·列传·方术列传下》
因此古之神仙常常引导人体运动，模仿熊鸱的动作，使腰部头部活动，关节运动，用来延缓衰老。
是以古之仙者，为导引之事，熊经鸱顾，引挽腰体，动诸关节，以求难老。
Therefore, immortals in ancient times often guide human body to exercise, imitating the movements of bear and owl, making waist and head move and joints exercise, this is used to delay senescence.