《旧唐书·本纪·卷十八》
中书省上奏百官的建议：九宫坛本为大祠，请降格为中祠。
中书奏百官议九宫坛本大祠，请降为中祠。
The Ministry of Zhongshu reported the suggestions of the officials to the emperor: The Nine Palace Altar was originally a large temple, so please demote it to a medium temple.