剑鞘保护剑的锋利，自己却满足於它自己的迟钝。
The seabbard is content to be dull when it protects the keenness of the word.
"The best and most beautiful things in the world cannot be seen or even touched - they must be felt with the heart."
The man who removes a mountain begins by carrying away small stones.
Machinery and labor-saving devices are only valuable as they serve to reduce the cost of manufacture.
史记
The writer is a person who writes, and the reader is a person who reads.