"In former times, our ancestors devoted great effort and energy to driving away our enemies and protecting our country, so that nowadays people are living in peace and prosperity. I want you all to remember the great sacrifices of your forbearers and show yourselves worthy of being their successors."

The king paused a moment and went on:

"As you already know, I am getting older. I intend to hand over the throne to one of you, but I don't know which one of you would have the ability and wisdom to lead the country. So, I decided to test your heart of conscience. Whoever among you could prepare the best dishes to offer to our ancestors and also satisfy my taste shall be succeeded to the throne."

One night after thinking about ways to make his father happy again, Tiet Lieu was exhausted and fell asleep. In his sleep, he saw an old man with white-silvered hairs approaching him and said: "Your devout and caring has touched my heart very deeply. You truly deserved the royal throne of your father. You don't have to go anywhere to find foods. It is just a waste of time and money. Of all the foods, rice is the most precious and valuable of all, yet very abundant. You find anywhere in your father's kingdom." Said the Fairy. "Go and use glutinous rice. Cook it very thoroughly then mould it into a round rice cake, and call it Banh Day. This will symbolize the sky you live under. Then do the same for the square rice cake. Stuff cooked bean paste and ground meat in the middle of the square rice cake and call it Banh Chung. This will symbolize the earth. Present these cakes to your father as offerings to your ancestors." Having said that, the Fairy disappeared.

After waking up, Prince Tiet Lieu was very happy and set out to do exactly what he was told in the dream. On the feast day, while the other princes brought along many different kinds of valuable gifts such as delicacies from the mountains and the sea, which were rarely found on earth, the youngest prince worshipped his ancestors with sweet rice cakes. After tasting each and every foods of Tiet Lieu's brothers, the King shook his head in disappointment. The king was very surprised when he saw the strange cakes presented by his youngest son. The king asked him what the cakes were made from and why he had chosen those cakes as offerings for his ancestors. The young prince then sincerely explained the meaning of each cake to his father.

After a moment of reflection, the king decided to select the youngest son’s gifts as offerings to Heaven, the Earth and their ancestors. When the worshipping was over, the king ordered the cakes to be cut and given to everyone to eat. They all agreed that the cakes had a very special flavor and taste that they had not ate before in their lives.

The King was so pleased that he decided to give his throne to Prince Tiet Lieu. He solemnly declared:

"The round cakes can stand for Heaven and I will name them "Banh Day". The square cakes can symbolize the Earth and I will call them "Banh Chung". Pork, rice, peas and "dong" leave can stand for animals and plants. The leaves wrapping the delicious inside imply mutual protection. The gifts are very meaningful and worthy of being presented to our ancestors as a token of their offspring’s deep gratitude. I am very pleased to declare that the throne should be ceded to your youngest brother."

After that, King Hung Vuong VI ordered that this recipe be passed out to all people in his kingdom. As the result, it has been a widely known in the Vietnamese customs. Every year during the New Year celebration, the Vietnamese people would cook Banh Chung and Banh Day, first as a tribute to their ancestors, and second to have as a good meal with the traditional flavor.