The original city gods were identical with earth gods, shown by the fact that the two characters meaning city god were derived from older characters meaning "city wall" and "moat."
整句話的意思是：天子在歲末所舉行的祭神大典，一共有八種，其中第七種是祭城隍。這種祭典至少已流傳了二千四百多年。原始祭祀的城隍是「地祇」，也就是土地神。因為城隍兩字就是由「城郭」和「隍濠」簡化而來。