《淮南子·精神训》
以上这些就是真人的行为表现。吹嘘呼吸，吐出污秽之气吸入新鲜空气，像熊悬吊、像鸟伸颈，如鸭浮水、如猿跳跃，像鹰环视、像虎回顾，做些动作的人只是想保养自己的身体，而真人却不必为这些导引之术烦恼。因为真人他即使精神飞扬激荡也不会丧失充实的精气，昼夜变化也不会伤害他，与万物一样有青春活力，这是在于他的品性合于道体，内心有着感应四时变化的能力。
若吹呴呼吸，吐故内新，熊经鸟伸，凫浴蝯躩，鸱视虎顾，是养形之人也，不以滑心，使神滔荡而不失其充，日夜无伤而与物为春，则是合而生时干心也。
The above are all behaviors of the true person. Blowing and breathing, breathing out the dirty air and breathing in the fresh air, like a bear hanging, like a bird stretching its neck, like a duck floating on water, like an ape jumping, like an eagle looking around, like a tiger looking back, people who do these movements just want to nourish their physical bodies, but the true person does not need to worry about these guiding arts. The true person, even if his spirit is wildly excited, will not lose his abundant vitality, and changes between day and night will not harm him. Like all things, he has youthful vitality, this is because his nature is in harmony with the Way, and his inner self has the ability to sense changes in the seasons.