When did the custom of worshiping the Kitchen Gods appear?

In the book Encyclopedia of Traditional Vietnamese Villages, Associate Professor Dr. Bui Xuan Dinh said that elements such as Tao Quan and Ngoc Hoang associated with Taoism appeared in our country quite late. In fact, December 23 is the day to worship the kitchen god, related to the custom of worshiping Mother Goddess from the matriarchal period. At that time, women played a big role in the family, society and even in marriage (marrying many husbands, one wife, two husbands).

He believes that the kitchen god is the god who governs kitchen work, not only daily meals but also maintains harmony and safety in the house - related to firewood and cooking. December 23 is also the day to honor fire and women - those who have the merit of discovering and keeping the fire (women have long been responsible for cooking and housework, with the mission of "keeping the fire" for the family, both literally and figuratively).

According to the ancients, December 23rd is the day when the "gates of heaven" open, which is the time when the three planets, the Sun, the Moon, and the Earth, are in the same orbit. If the Kitchen Gods arrive on the wrong day, the "gates of heaven" will close, so they cannot enter to report to the Jade Emperor. According to folk beliefs, noon on December 23rd is the time when the Kitchen Gods fly to heaven. Therefore, the worship must be performed before this time. The best time is from the evening of December 22nd to noon on the 23rd.

In yin and yang, carp symbolizes yin, identical to the moon, so it can fly. And only carp can transform into a dragon. Therefore, releasing carp on the 23rd of December carries the concept of sending the Kitchen God to heaven, and at the same time expresses the people's wishes for a prosperous new year, with all good things.

Author Minh Duong in Folk Rituals - Ancestor Worship Rituals wrote that among the gods, Tao Quan is the god who closely follows the lives of people with the role of the Jade Emperor's "hands and feet" to every home. Every day, Tao Quan records the merits and sins, good and bad, of everyone so that when he returns to heaven, he can report to the Jade Emperor, as a basis for rewarding the good and punishing the bad. Therefore, to receive Tao Quan's support, people often hold a very solemn ceremony to send Tao Quan to heaven.

According to folk beliefs, Mr. Cong is the god who governs the land in the house, Mr. Tao are the three kitchen gods who oversee the family's kitchen. Professor Dr. Vu Gia Hien, Director of the Center for Research and Application of Cultural Tourism, said that the ceremony on the 23rd of December is a ceremony to send Mr. Cong and Mr. Tao to heaven, so it is incorrect for people to combine the offerings on the altar.

Mr. Cong is worshiped on the main altar in the house with the ancestors, Mr. Tao must be worshiped in the kitchen, can be next to or above the kitchen, showing the folk belief of worshiping the god who controls the kitchen in each family with the wish to keep the kitchen fire always warm, the family harmonious and prosperous.