In 594 BC, King Zhuang of Chu led his army to attack the State of Song. The State of Song sent Yue Yingqi to the State of Jin to ask for help. Duke Jing of Jin, displeased with Chu's bullying of the weak, prepared to dispatch troops to assist Song.

However, Minister Bo Zong advised against it, stating that Jin was beyond reach (鞭长莫及). He then said, "An old saying goes, 'High and low are in one's heart.' Rivers and swamps take in filth (川泽纳污), mountains and thickets conceal dangers (山薮藏疾), fine jades hide minor flaws (瑾瑜匿瑕), and a ruler endures disgrace (国君含垢) – this is the way of Heaven."

This story, particularly the phrases '川泽纳污' and '山薮藏疾,' which mean 'rivers and swamps take in filth' and 'mountains and thickets conceal dangers' respectively, illustrates the concept of accommodating and concealing impurities or evils, contributing to the later meaning of the idiom '藏污纳垢'.