Why do people buy zongzi or wrap zongzi every Dragon Boat Festival?

According to the historian Biography of Qu Yuan and Jia Sheng, Qu Yuan was a minister of Chu Huaiwang in the Spring and Autumn Period. He advocated the use of talents, empowerment, and prosperity, and advocated joint resistance to Qin, which was strongly opposed by others. Qu Yuan was forced to leave his post, was driven out of the capital and exiled to the Yuan and Xiang river basins. During his exile, he wrote immortal poems such as Li Sao, Tian Wen and Tian Wen, which have a unique style and far-reaching influence (therefore, the Dragon Boat Festival is also called the Poet's Day). In 278 BC, Qin Jun conquered Kyoto of Chu. Seeing that his motherland was invaded, Qu Yuan was heartbroken, but he was always reluctant to give up his motherland. On May 5th, after writing his masterpiece Huai Sha, he died in Miluo River and wrote a magnificent patriotic movement with his own life.

Legend has it that after Qu Yuan's death, the people of Chu were so sad that they flocked to the Miluo River to pay homage to Qu Yuan. The fisherman paddled the boat and fished for his real body back and forth on the river. A fisherman took out rice balls, eggs and other foods prepared for Qu Yuan and threw them into the river, saying that ichthyosaurs, shrimps and crabs were full and would not bite the doctor. People followed suit after seeing it. An old doctor took an altar of realgar wine and poured it into the river, saying that he would stun the dragon water beast with medicine so as not to hurt Dr. Qu. Later, people were afraid that rice balls would be eaten by dragons, so they came up with the idea of wrapping rice with neem leaves and then wrapping it with colored silk to make it develop into brown seeds.

After that, on the fifth day of May every year, there is the custom of dragon boat racing, eating zongzi and drinking realgar wine. In memory of the patriotic poet Qu Yuan.