Why do people eat dumpling at Dragon Boat Festival?

Dragon Boat Festival
5th day of the 5th lunar month

Qu Yuan
The Dragon Boat Festival, also called the Duanwu Festival, is celebrated on the fifth day of the fifth month according to the Chinese calendar. For thousands of years, the festival has been marked by eating zong zi (glutinous rice（糯米）wrapped to form a pyramid using bamboo or reed leaves) and racing dragon boats.

The festival is best known for its dragon-boat races, especially in the southern provinces where there are many rivers and lakes. This regatta（赛舟会）commemorates the death of Qu Yuan , an honest minister who is said to have committed suicide by drowning himself in a river.

Qu was a minister of the State of Chu situated in present-day Hunan and Hubei provinces, during the Warring States Period (475-221BC)（战国时期）. He was upright, loyal and highly esteemed for his wise counsel that brought peace and prosperity to the state. However, when a dishonest and corrupt prince vilified Qu, he was disgraced and dismissed from office. Realizing that the country was now in the hands of evil and corrupt officials, Qu grabbed a large stone and leapt into the Miluo River on the fifth day of the fifth month. Nearby fishermen rushed over to try and save him but were unable to even recover his body. Thereafter, the state declined and was eventually conquered by the State of Qin.

The people of Chu who mourned the death of Qu threw rice into the river to feed his ghost every year on the fifth day of the fifth month. But one year, the spirit of Qu appeared and told the mourners that a huge reptile（爬行动物）in the river had stolen the rice. The spirit then advised them to wrap the rice in silk and bind it with five different-colored threads before tossing it into the river.

During the Duanwu Festival, a glutinous rice pudding called zong zi is eaten to symbolize the rice offerings to Qu. Ingredients such as beans, lotus seeds（莲子）, chestnuts（栗子）, pork fat and the golden yolk of a salted duck egg are often added to the glutinous rice. The pudding is then wrapped with bamboo leaves, bound with a kind of raffia and boiled in salt water for hours.

The dragon-boat races symbolize the many attempts to rescue and recover Qu's body. A typical dragon boat ranges from 50-100 feet in length, with a beam of about 5.5 feet, accommodating two paddlers seated side by side.

A wooden dragon head is attached at the bow, and a dragon tail at the stern（船尾）. A banner hoisted on a pole is also fastened at the stern and the hull is decorated with red, green and blue scales edged in gold. In the center of the boat is a canopied shrine behind which the drummers, gong（铜锣）beaters and cymbal（铙钹）players are seated to set the pace for the paddlers. There are also men positioned at the bow to set off firecrackers, toss rice into the water and pretend to be looking for Qu. All of the noise and pageantry creates an atmosphere of gaiety and excitement for the participants and spectators alike. The races are held among different clans, villages and organizations, and the winners are awarded medals, banners, jugs of wine and festive meals.

Dragon Boat Festival, Duanwu Festival or Tuen Ng Festival is a traditional Chinese festival held on the fifth day of the fifth month of the Chinese calendar (19/June/07 & 08/June/08). It is also known as the Double Fifth. It has since been celebrated in other parts of East Asia as well. In the West, it is commonly known as Dragon Boat Festival and is typically celebrated during the summer months with dragon boat races and competitions being the focus of the festivities.
The origins of Duan Wu originated in ancient China. One traditional view holds that the festival memorializes the officer Qu Yuan (c. 340 BC-278 BC) of the Warring States Period. He committed suicide by drowning himself in a river because he found out that the Chu government had lost a battle. The local people, knowing him to be a good man, decided to throw food into the river to feed the fish so that they would not eat Qu Yuan's body. They also sat on long, narrow paddle boats called dragon boats, and tried to scare the fish away by the thundering sound of drums aboard the boat and the fierce looking carved dragon head on the boat's prow. Another popular legend holds that after Qu Yuan committed suicide, because the people loved him so much, they raced out to recover his body, and the races signify the boats skimming across the water to find him. However, research has also revealed that the festival is also a celebration that is characteristic of ancient Chinese agrarian society: the celebration of the harvest of winter wheat, because similar celebrations had long existed in many other parts of China where Qu Yuan was not known. As interactions between Chinese residing in different regions increased, these similar festivals were eventually merged.
In the early years of the Republic of China, Duan Wu was also celebrated as "Poets' Day," due to Qu Yuan's status as China's first poet of personal renown.
Today, people eat bamboo-wrapped steamed rice dumplings called zongzi (the food originally intended to feed the fish) and race dragon boats in memory of Qu Yuan's death.