《周书·列传·卷三十四》
荣阳郑孝穆经常对堂弟郑文直说： 裴长宽兄弟之间，天伦深厚和睦，是人的表率。
荥阳郑孝穆常谓从弟文直曰： 裴长宽兄弟，天伦笃睦，人之师表。
Zheng Xiaomu of Rongyang often said to his cousin Zheng Wen Zhi: "The Pei Changkuan brothers are a model for people in terms of their deep and harmonious family ties."