《韩非子·显学》
当初大禹疏通江河。而民众却用瓦石去填塞；子产提倡开荒种桑，而郑国民众却要责骂。
昔禹决江濬河而民聚瓦石，子产开亩树桑郑人谤訾。
In the past, when Yu the Great dredged the rivers, the people used rocks and tiles to block them up. When Zichan promoted land reclamation and planting mulberry trees, the people of Zheng State scolded him.