《魏书·列传·卷四十八》
魏高祖曾经下诏书告示群官： 自近代以来，出身高低，总有一定的分别。
高祖曾诏诸官曰： 自近代已来，高卑出身，恆有常分。
Wei Gaozu once issued an edict to proclaim to the officials: Since modern times, there has always been a certain distinction between high and low.