《汉书·志·礼乐志》
帝王一定要根据前代帝王的礼，顺应时代的要求加以施行，进行增删，按照百姓的想法，逐渐制作，至天下太平时就完备了。
王者必因前王之礼，顺时施宜，有所损益，即民之心，稍稍制作，至太平而大备。
The emperor must implement it in accordance with the etiquette of the previous emperors and adapt to the requirements of the times, and make additions and deletions, and gradually make them according to the people's ideas, and they will be complete when the world is peaceful.