《论衡·卷一·气寿篇》
百岁的寿命，大概是人年龄的正常寿限，就像植物到秋死去，是植物生命的正常期限。
百岁之寿，盖人年之正数也，犹物至秋而死，物命之正期也。
The life span of a hundred years is probably the normal life limit of a human, just like a plant that dies in autumn, is the normal life limit of a plant.