when the sun reaches its zenith it must decline,when the moon is full it must wane ❍ 语曰： “～。”物盛则衰，天地之常数也。(《史记·范雎蔡泽列传》) The proverb says，“When the sun reaches its zenith it must decline,when the moon is full it must wane,and what is ripe must decay.” This is a universal law.