It is useless attacking the insensible.
这个故事带出的启示就是：想从守财奴那裡得到利益是十分愚蠢的。
A Serpent in the course of its wanderings came into an armourer's shop. As he glided over the floor he felt his skin pricked by a file lying there. In a rage he turned round upon it and tried to dart his fangs into it; but he could do no harm to heavy iron and had soon to give over his wrath.
有条蝮蛇爬进铁匠舖裡，要各种工具接济他。从他们那裡得到救济之后，又爬到剉刀那裡，请他也给东西。剉刀说：「你若想从我这裡得到点东西去，那你真是太傻了，我歷来取之於人，却从不施捨。」