《史记·七十列传·仲尼弟子列传》
一年间，陈旧的谷子吃完了，新的谷子又成熟了，钻木取火的木材换遍了，守丧一年也就可以了。 
旧穀既没，新穀既升，钻燧改火，期可已矣。 
Within a year, the old millet is finished, new millet has ripened, and the firewood for drilling wood to make fire has been changed, so one year of mourning is enough. 