During the Xianfeng period of the Qing Dynasty, a military attache named Zhang Yao was promoted to Henan Ambassador because of his hard work and outstanding exploits. He was out of school and uneducated since childhood, and was often discriminated against by courtiers. Liu Yunan, an imperial envoy, said he was "illiterate" and appointed him as the company commander. From then on, Zhang Yao decided to study hard to make himself literate and military. Zhang Yao thought his wife was very cultured, so he went home and asked her to teach him. The wife said: teaching is ok, but there is one condition, that is, learning from teachers. Zhang Yao readily promised, immediately put on royal robes, and let his wife sit in front of Confucius memorial tablet, making three obeisances and nine knocks. Since then, his wife has taught him to read the history of the Bible in her spare time. Whenever his wife puts on a teacher's airs, he bends down to listen to the training and dares not be rude. At the same time, he also had an "illiterate" seal engraved, which he often wore to protect himself. A few years later, Zhang Yao finally became a very learned man. Later, when he was a governor in Shandong, someone was "illiterate" with him. He wrote to the emperor asking for an interview. The interview results surprised the emperor and many ministers. Zhang Yao took office in Shandong, repaired river banks, built roads, set up factories and bureaus, and made fine works, and did many things that benefited the country and the people. Because he was diligent and studious, the emperor named him "the fruit of diligence" after his death.