《隋书·帝纪·卷三》
初十，征调黄河以北十余郡的成年男子开凿太行山，直达并州，以使驰道畅通。
戊午，发河北十余郡丁男凿太行山，达于并州，以通驰道。
On the 10th day of the first month, adult males from more than ten counties north of the Yellow River were recruited to cut through Taihang Mountain, directly to Bingzhou, so that the roads could be clear.