《淮南子·说林训》
蒙上灰尘就会眯起眼睛，这是理所当然的；但说他不出门就被尘土蒙眯了眼睛，这就不合情理了。
蒙尘而眯，固其理也；为其不出户而堁之也。
It is natural to squint when covered with dust, but it is unreasonable to say that his eyes are covered with dust without going out.