《汉书·传·西域传下》
新道所在地与匈奴南将军地连接，徐普想划明此界限以报告皇上，就召姑句，让他帮助证明。
地又颇与匈奴南将军地接，曾欲分明其界然后奏之，召姑句使证之，不肯，系之。
The new road was connected to the southern general of the Xiongnu. Xu Pu wanted to clarify the boundaries and report it to the emperor, so he summoned Guju and asked him to help prove it.