《水经注·卷十九》
光武帝去问公卿，大中大夫张湛说：仁爱的人不遗弃旧友，忠贞的人不忘记君主，这是德行崇高的人啊！
帝问公卿，大中大夫张湛曰：仁不遗旧，忠不忘君，行之高者。
Emperor Guangwu questioned the high ministers, and the Grand Master of the Masters of the Palace Zhang Zhan said: Benevolent people do not abandon old friends, the loyal do not forget their sovereign, these are people of high morals!