《管子·君臣下》
所以说，做君主的要主持宽仁，做臣子的要谨守信用，这就是所说的上下之礼。
故曰：君人者制仁，臣人者守信。此言上下之礼也。
Therefore, it is said of the ruler that he should be magnanimous, and of the minister that he should be faithful. This is called the "etiquette between the upper and lower orders."