《魏书·列传·卷八十三》
太祖又令将士沿汾水一带的山丘树立栅栏，长达数十里，用来防卫割草放牧的人。这一年九月，姚兴从汾水西面北下，凭靠山壑构筑堡垒用以防守。
太祖知兴气挫，乃南绝蒙坑之口，东杜新坂之隘，守天渡，屯贾山，令平水陆路绝，将坐甲而擒之。
The emperor also ordered his men to build fences along the hills beside the Fen River, over a distance of several tens of miles, to protect the men gathering firewood and grazing livestock. In the ninth month of that year Yao Xing came downstream from the west along the Fen River, and built fortresses in the valleys as defences.