《淮南子·齐俗训》
在山林中柴薪难以出售，在湖区鱼虾不易出让，因为这种地方有的是这类东西。
林中不卖薪，湖上不鬻鱼，所有余也。
In mountainous areas the sale of firewood is weak, just as it is in lake regions for fish and shrimp because they are abundant in these areas.