《资治通鉴·魏纪·魏纪七》
自光武帝以来，分封诸王有一定制度，只允许他们在宫内自娱自乐，不得统治百姓和参与政事，与宾客交往，都有严格的禁令；这样才得以保全安定，各自安享福禄，这就是前代得失的经验教训。
自光武以来，诸王有制，惟得自娱于宫内，不得临民，干与政事，其与交通，皆有重禁，遂以全安，各保福祚，此则前世得失之验也。
Since the Emperor Guangwu, the enfeoffment of the princes has been regulated by a system. They are only allowed to amuse themselves within the palace and are not allowed to rule the people or participate in politics. Even their contact with guests is strictly prohibited. Only this way can they preserve their peace and security and each enjoy his own blessings. This is a lesson learned from the successes and failures of the previous generations.