《容斋随笔·卷十一·汉唐封禅》
唐贞观六年，又请求，皇上说： 你们都把祭拜天地的典礼看成是帝王的盛大的事情，我的想法不是这样的。
六年，复请，上曰： 卿辈皆以封禅为帝王盛事，朕意不然。
In the sixth year of the Zhenguan era of Tang, they requested again, and the emperor said: “You all see the ceremony of worshiping Heaven and Earth as a great imperial event, but that is not how I think about it.