If you talk about the Tang Dynasty, everyone in the world will think of the situation of blooming flowers, will think of the wealth of this dynasty, and will also regard it as the pride of Chinese history. However, the prosperity of the pole must decline is an immutable law in the world, and a "anshi rebellion" took away the prosperity of the Tang Dynasty and brought it to the road of decline.
In the face of these changes, many patriotic people have sprung up with countless worries in their hearts, including Du Fu. During the Anshi Rebellion, Du Fu once wrote a poem and used it to lament the misfortune of the country, but hundreds of years later, the poem was called military intelligence.
"Spring Hope"
Du fu
The country is broken by mountains and rivers, and the city is deep in spring grass and trees.
When I feel the flowers splash tears, I hate the birds and be frightened.
The flames lasted for three months, and the family letter arrived at ten thousand gold.
The white head scratches are shorter and more overwhelming.
"Spring Hope" is one of Du Fu's most classic works, the first four sentences of this poem write about the miserable and dilapidated scene of Chang'an in the spring, full of rise and fall, and in the last four sentences, the author writes his own feelings of caring for his relatives and caring about state affairs, full of bitter mourning.
The whole poem is exquisite in battle, and the voice is tragic, which fully shows the poet's patriotic feelings. Obviously, this is a poem depicting the author's melancholy, and it is also a poem in which the author expresses his patriotic feelings. What no one expected, however, was that many years later, during the Song Dynasty, the poem became an intelligence.
We all know that the Song Dynasty was a unified dynasty after the Tang Dynasty, and it was also a relatively peculiar dynasty. Due to the Song Dynasty's strategy of emphasizing literature over force, the Song Dynasty period became an era of competition between the Central Plains and the grasslands. During this period, the Central Plains and the steppe were in constant conflict, and accompanied by thrilling military and political struggles, and the espionage struggle on the hidden front was equally fierce.
Generally speaking, where there was war, intelligence was needed, and in order to deliver information, the Song Dynasty used a code that is now known to the world, which was called "character test" at that time. What is a "word test"? This is recorded in the Song Dynasty's military textbook "General Outline of the Martial Classics".
During the Song Dynasty, there were about 40 military activities involved, and the so-called "character test" was to find a poem of forty characters and replace these different military activities with different words in the poem, such as "Spring Hope" is one of them.
If in this poem, people use the word "gold" in the "family letter to ten thousand gold" to mean "there are many thieves", then the front-line commanders can make a special mark on the word "gold" when sending intelligence personnel to the rear to deliver information. After receiving the information in the rear, you can check it according to the codebook to understand the information of the enemy in front of you. As a result, the information was transmitted to the army of the Song Dynasty.
References: Old Book of Tang, Quan Tang Poetry