《周书·列传·卷十二》
太祖刚担任丞相时，开始封立这个郡，但从未赐给别人，到这时才封给宇文贵。
太祖之初为丞相也，始封此郡，未尝假人，至是封贵焉。
When Emperor Taizu had just assumed the post of Grand Minister, he established this commandery but had never awarded it to anyone, until he awarded it to Yuwengui.