What does it mean to write a book without words?

In order to govern the country, it takes many times of tempering and experience. This sentence comes from a poem in the Song of Lushan Mountain: The Emperor Nostalgia by Du Fu, a poet in the Tang Dynasty. Among them, "all talents are tempered by the state" is to govern the country, and it takes many tempering and experience to cultivate talented talents. "Writing a book without words will last forever" means that people who write books cannot leave the immortal fame of words. The whole sentence means that in order to govern the country, it takes many times of tempering and experience to train talents, and talents need to write books and leave eternal fame. This sentence conveys the importance of "governing the country and keeping the country safe and cultivating talents" and the value and significance of "writing books and saying things".