《资治通鉴·晋纪·晋纪九》
拓跋猗卢因为封邑代郡距离自己的国家遥远，百姓连接不在一起，于是率领部落一万多家从云中进入雁门，向刘琨索求陉岭以北地区。
猗卢以封邑去国悬远，民不相接，乃帅部落万馀家自云中入雁门，从琨求陉北之地。
Since Tuoba Yilu's enfeoffed territory, the Dai commandery was quite distant from his own country, and the people were not connected, so he led more than ten thousand households of his tribe from Yunchong into Yanmen, and asked Liu Kun for the territory north of Xingling.