《资治通鉴·汉纪·汉纪十一》
因此，汉武帝欣然同意了张骞的建议，命张骞从蜀郡、犍为派王然于等人作为使者，由、冉、徙及邛、间四道向身毒国进发。各路使者分别走出一二千里之后，北路被阻于氐？南路被阻于、昆明。
乃令骞因蜀、犍为发间使王然于等四道并出駹，出冉，出徙，出邛、僰，指求身毒国，各行一二千里，其北方闭氐、莋，南方闭巂、昆明。
Emperor Wu readily agreed to Zhang Qian's suggestion and made Zhang Qian send Wang Ran and other people as messengers from Shujun and Jianwei to set out, via Ye, Ran, Xi as well as Qiong, Jian on four routes to Shen du Guo. After the messengers on each route traveled one or two thousand li, the northern route was blocked at Di. The southern route was blocked at Kunming.