佛祖統紀 35.6

35.6

In the first year of Yuanshou, previously, Marquis of Bowang Zhang Qian returned from the Yuezhi (a state in the Western Regions) and stated: 'When your servant was in Daxia (name of a state), I saw bamboo canes from Qiong and cloth from Shu. I asked how they obtained these. The people of that state said: "Our merchants bought them in Shendu (which is Tianzhu)." Shendu lies several thousand li southeast of Daxia. This cannot be far from Shu.' Thereupon, [the Emperor] ordered Qian, by way of Qianwei in Shu (present-day Jiazhou), to dispatch secret envoys such as Wang Ranyu to head for Shendu (meaning undercover reconnaissance; also, envoys were sent in alternate years, accounts vary). For over four years, all were blocked by the Kunming and none could pass through (blocked by the Kunyi).