《淮南子·说林训》
树木正茂盛时，即使整天采伐也不显衰败凋敝；而秋风一刮，寒霜一打，一夜间树叶都落光。
木方茂盛，终日采而不知；秋风下霜，一夕而殚。
When the trees are flourishing, even if they are felled all day long, they will not show signs of decay and decline; but when the autumn wind blows and the frost hits, all the leaves will fall overnight.