It strengthens the lord of water to control sunlight; it benefits the source of fire to eliminate yin and shade. It is a brilliant commentary made by Wang Bing in the Tang Dynasty according to “Su Wen – The Great Treatise on the Supreme Truth” that “all cold but hot is taken from yin, hot but cold is taken from yang”, which brings into full play the theory of cold and heat, deficiency and reality, yin and yang, water and fire. “The balance and coordination of yin and yang is the basis of human physiological activities and the guarantee of human health. When this balance and coordination is disrupted and yin and yang are out of balance, disease will occur. Therefore, imbalance of yin and yang is the basis of disease. If the yang in the body is deficient, the ability to push and warm is significantly reduced, and the yang deficiency cannot control the yin and the yin is relatively strong; “yang deficiency produces cold deficiency”, which can be seen clinically as pale face, cold extremities, fatigue, curled up, spontaneous sweating and other signs of cold deficiency; if the yin in the body is deficient If the body is deficient in yin, moistening and nourishing, yin deficiency can not control yang, then yang is relatively hyperactive; “yin deficiency produces deficiency heat”, clinical manifestations of deficiency heat can be seen in low fever, hot flashes, night sweats, five heartburn, red tongue with little coating, thin pulse, etc. 1, the main of the strong water to control the sun “all cold and heat is taken from the yin”, refers to the use of bitter cold drugs to treat heat evidence, this heat does not reduce, but more serious. This means that this heat is not a surplus of real heat, but a deficiency heat caused by Yin deficiency (mostly liver and kidney Yin deficiency), a deficiency fire caused by deficiency, that is, not a surplus of fire, but a deficiency of water; therefore, we should nourish Yin and strengthen water to suppress Yang fire exuberance: strengthen the main of water to control the sun. This “water” refers to kidney water, that is, kidney essence, which is transformed into kidney yin and kidney yang; kidney is the house of water and fire, kidney yang. Kidney fire is the driving force to produce heat and function in the whole body; while kidney water and kidney yin are the material basis to produce function in the whole body, and only with material can function be produced. It is like a Hercules, powerful and strong, but if he is not given food and water for three days, the Hercules will feel dizzy and dizzy, and his body will be weak, so he will not be able to talk about any function. Therefore, function and substance (kidney yang, kidney fire and kidney yin, kidney water) are mutually rooted, two aspects of contradiction and unity, one is indispensable; use the formula of nourishing yin and nourishing liquid to restore yin and make yang heat recede. 2. Benefit the source of fire to eliminate yin and shade. “The source of all heat but cold is taken from Yang” means that if the cold evidence is treated with pungent and hot drugs, and the disease does not heal but is cold, it is not actual cold, but Yang deficiency, and Yang deficiency produces cold. The kidney is the origin of the innate nature, which is the source of fire; the spleen is the origin of the postnatal nature, which can transport the essence of water and grain and moisten the whole body; the innate nature depends on the warmth of the postnatal nature. Therefore, in a comprehensive manner, the source of fire is the kidney and spleen. “Benefiting the source of fire” refers to warming the kidney yang and spleen yang. Yin and shade”, as opposed to “sunlight”, refers to water-dampness and cold evil. Eliminating shade means removing water dampness and cold evil; using warming and tonifying prescriptions for yang energy, so that yang energy will be restored and yin and cold will disappear. To sum up, the treatment for deficiency cold and deficiency heat does not lie in dipping its cold or heat, but in tonifying Yang to control Yin and nourishing Yin to nourish Yang; “strengthen the main body of water to control sunlight, and benefit the source of fire to eliminate yin and yang” in order to adjust the bias of Yin and Yang and to calm the period.