《太平广记·卷一百八十七·职官》
君王应该无戏言，说话若有失误，则取罪于天下，失信于天下老百姓。
盖天子无戏言，言之苟失，则取尤天下。
The monarch should not make light remarks; if he makes a mistake in his words, he will draw blame from the entire world and lose the trust of all the people.