On the day of the Mid-Autumn Festival, people eat mooncakes to symbolize "reunion." The mooncake is also called Hu Biscuit, Palace Biscuit, Moon Cake, Harvest Cake, Reunion Cake, etc., and it was originally an offering used in ancient Mid-Autumn Festival rituals to worship the moon deity. According to historical records, as early as three thousand years ago during the Yin and Zhou dynasties, there were already "thin-edged, thick-centered Grandmaster Cakes" made to commemorate Grandmaster Wen Zhong. During the Han Dynasty, Zhang Qian traveled to the Western Regions and introduced walnuts and sesame seeds, leading to the creation of round "Hu Biscuits" filled with walnut kernels. In the time of Emperor Gaozong of the Tang Dynasty, General Li Jing returned victoriously from a campaign against the Xiongnu on the Mid-Autumn Festival. At that moment, a Tibetan merchant happened to present a Hu Biscuit. Emperor Taizong (Li Yuan) was delighted and, holding the Hu Biscuit, pointed to the bright moon in the sky and said: "We should invite the toad (the moon) with this Hu Biscuit." He then distributed the biscuits among his ministers. If this account is true, it might be the beginning of sharing mooncakes during the Mid-Autumn Festival. However, the term "mooncake" first appeared in Hongling Cake mentioned by Wu Zimu in the Southern Song Dynasty. Mooncakes are round and have been imbued with the meaning of reunion since the Ming Dynasty. Liu Tong wrote in "The Scenic Spots of the Imperial Capital": "On the 15th day of the eighth lunar month, people worship the moon, and their sacrificial fruit cakes must be round." Tian Ruocheng wrote in "The West Lake Excursion Notes": "The 15th day of the eighth lunar month is called the Mid-Autumn Festival, during which people give each other mooncakes, symbolizing reunion." Shen Bang recorded in "Miscellaneous Records of Wan Prefecture" the grand scene of making mooncakes in Beijing during the Ming Dynasty: "The townsfolk all make mooncakes and give them to each other, varying in size, calling them mooncakes. The shops even use fruits as fillings, creating various ingenious shapes and names, with some mooncakes worth hundreds of coins." Ingenious cake makers innovated and created various patterns on mooncakes. Peng Yunzhang described in "Yanzhou Folklore Chant": "Moon Palace Talismans, painted as jade rabbits residing in the kiln; Moon Palace Cakes, made into the image of silver toads in the purple celestial palace. A pair of toads fills the human world, regretting the year when Chang'e stole the elixir; rushing into the vast cold palace, unable to return, vainly laboring the jade pestle to preserve her red beauty."