《后汉书·列传·西域传》
元帝时，延曾经当过侍子，在京师长大，他仰慕喜爱中央大国，因此也参考汉的制度法律。
元帝时，尝为侍子，长于京师，慕乐中国，亦复参其典法。
During the time of Emperor Yuan, Yan once served as a son of a servant and grew up in the capital. He admired and loved the central power, so he also referred to the Han system and laws.