Spring belongs to wood in the five elements, which mainly grows and rises, corresponding to the characteristics of human liver and gallbladder; Summer is a fire, and the warmth rises, corresponding to the human heart and small intestine; The late summer is soil, bearing and receiving, corresponding to the human spleen and stomach; Autumn is golden, which governs health and harmony, corresponding to human lungs and large intestine; Winter is water, mainly downward, wet and cool, corresponding to human kidney and bladder. Raise the corresponding parts of the human body (internal organs) at the corresponding time. For example, spring is the best time to nourish and protect the liver.