Because there is only one harvest of rice and millet in autumn in northern China, and August 15 is the birthday of the land god, we chose to offer one of the spell offerings of steamed taro to the land god on August 15.
1279, Mongolian nobles destroyed the Southern Song Dynasty, established the Yuan Dynasty, and brutally ruled the Han people. Mafa defended Chaozhou against the Yuan Dynasty. After the city was broken, the people were slaughtered. In order not to forget the suffering of Hu people's rule, later generations used taro as a homonym with "Hu tou", which looked like a human head, in order to pay homage to their ancestors and pass it on from generation to generation, and it still exists today.
Solemnly declare: the answer is for reference only, please don't be blindly superstitious.