《资治通鉴·梁纪·梁纪八》
萧宝寅包围了冯翊县城，没有攻下。长孙稚的军队到了恒农，行台左丞杨侃对长孙稚说： 从前魏武帝曹操跟韩遂、马超在潼关交战，相持不下，韩遂、马超的才能，远不能与魏武帝相匹敌，但是却很长时间决不出胜负来，原因就在于韩遂、马超扼守住了险要关口。
萧宝寅围冯翊，未下；长孙稚军至恒农，行台左丞杨侃谓稚曰： 昔魏武与韩遂、马超据潼关相拒，遂、超之才，非魏武敌也，然而胜负久不决者，扼其险要故也。
Xiao Baoyin besieged Fengyi County but failed to capture it. When Changsun Zhi's army arrived at Hengnong, Yang Kan, the left chancellor, said to Changsun Zhi: "In the past, Wei Wu Emperor Cao Cao fought against Han Sui and Ma Chao at Tongguan, but they were evenly matched. Han Sui and Ma Chao's talents were far inferior to Wei Wu Emperor's, but they were able to fight for a long time without a clear winner. The reason was that Han Sui and Ma Chao were blocking the key pass.