《资治通鉴·汉纪·汉纪二十三》
杜邺劝说皇上： 唐尧、虞舜时期以及夏、商、周三个朝代，都分封了诸侯，用以达到天下太平的美好目的，因而燕侯、齐侯的承袭与周朝一并传续，子子相继、兄弟互接，历年不断。
杜业说上曰： 唐、虞、三代皆封建诸侯，以成太平之美，是以燕、齐之祀与周并传，子继弟及，历载不堕。
Du Ye persuaded his majesty: During the periods of Emperor Yao, Emperor Shun and the three dynasties of Xia, Shang and Zhou, feudal lords were all enfeoffed in order to achieve the beautiful goal of peace in the world. Therefore, the titles of the Princes of Yan and Qi continued to be passed down in the Zhou Dynasty, from generation to generation, and brothers and sisters took over each other, and they have continued over the years.