《周书·本纪·卷三》
孝闵帝下韶说： 我本源自神农氏，在圆坛和方坛二丘，都应设立控垦压的神主。
诏曰： 予本自神农，其于二丘，宜作厥主。
Emperor Xiaomin issued a decree, stating: “I originated from Shennong. Both Round Altar and the Square Altar should establish the principal deity to control reclamation exploitation.”