《资治通鉴·唐纪·唐纪一》
当时天下还不安定，凡是边远重要的州郡，都设置总管府，以统帅几个州的军队。
时天下未定，凡边要之州，皆置总管府，以统数州之兵。
At that time, the world wasn't stable, and prefectures in important and remote places all set up headquarters to command troops from several prefectures.