《史记·三十世家·郑世家》
子产对韩宣子说： 执掌政权一定凭仁义道德，不要忘记政权巩固的原因。 
子产谓韩宣子曰： 为政必以德，毋忘所以立。 
Zichan said to Han Xuanshu: When exercising political power, one must rely on benevolence and righteousness and not forget the reason for the consolidation of power.