During the Tang Xiantian era (712-13 CE), Du Sheng of Xuzhou was a skilled diviner. He reported on people who had abandoned their posts, and these was all verified, as if he were a deity. There was someone who had lost a slave and came to Du to ask about them. Sheng told him: “You only need to search along the post-road. On the way you’ll meet a courier bearing a good whip. Kowtow and beg for it. If they don’t hand it over, say with feeling that Du Sheng told you to ask for it. You will then certainly find them.” He did as he had been instructed, and did indeed encounter a courier, begging for the whip as Du Sheng had said. The envoy found this strange, and said: “I don’t grudge you the whip, but without it how could I urge on my horse? You should snap off a branch from the left side of the road to exchange, then I will hand you the whip.” When he went to break one, he spotted the lost slave hidden beneath a tree, and captured them. When asked about the matter, the slave said: “While fleeing along the road, I caught sight of the gentleman in the distance, so concealed myself here.”
When another person who had lost a slave visited Du Sheng, Sheng told them: “Return, taking five hundred cash, and wait with it on the public road. When you see an envoy bearing sparrowhawks pass by, ask to buy one. You will certainly regain the slave.” He did as instructed and waited. Presently there was an envoy with sparrowhawks, so he made his request and asked to buy one. The envoy thought this strange but cut one free to hand over. Just as he was about to take hold of it, the hawk suddenly took wing and escaped. When he went to fetch it, the slave was indeed found hiding beneath, and was captured. There who were reported on by him were numerous, but there is no space to tell of them here. From Jiwen.
Li Fang 李昉, et al., Taiping guangji 太平廣記 (Extensive Gleanings from the Era of Great Harmony), 10 vols (Beijing: Zhonghua shuju, 1961), ii, 77.484:
杜生
唐先天中。許州杜生善卜筮。言走失官祿。皆驗如神。有亡奴者。造杜問之。生曰。汝但尋驛路歸。道逢驛使有好鞭者。叩頭乞之。彼若不與。以情告云。杜生教乞。如是必得。如其言。果遇驛使。以杜生語告乞鞭。其使異之曰。鞭吾不惜。然無以撾馬。汝可道左折一枝見代。予與汝鞭。遂往折之。乃見亡奴伏於樹下。擒之。問其故。奴曰。適循道走。遙見郎。故潛于斯。復有亡奴者見杜生。生曰。歸取五百錢。於官道候之。見進鷂子使過。求買其一。必得奴矣。如言候之。俄有鷂子使至。告以情。求市其一。使者異之。以副鷂子與焉。將至手。鷂忽飛集于灌莽。乃往取。奴果伏在其下。遂執之。言人祿位中者至多。茲不縷述。出紀聞