The Tānksūqnāma-yi Īlkhān dar Funūn-i ‘Ulūm-i Khiṭāʾī (The Treasure Book of the Ilkhan [Öljeitü, r. 1304-1316] on Chinese Science and Techniques) is the first book-length translation of Chinese medicine into an Islamic language (Persian). It survives in a single manuscript. The manuscript was copied in Tabriz, likely in Ilkhanid vizier, historian, and theologian, Rashid al-Din’s (d. 1318) scriptorium in the Rabʿ-i Rashīdī, in the hijri year 713 (/1313), that is, during his lifetime. In addition to the work’s translation of an assortment of medical guides dealing with the principles of Chinese medicine, physiology, and traditional pulse theory (sphygmology), it also includes a forty-some folio-preface penned by the vizier that discusses various topics related to China - from the mysteries of Chinese language and script to Chinese print and medical practices. This paper examines this long preface to explore some of the methods Rashid al-Din experiments with to legitimate this translation project which seems to have encountered Muslim resistance. Specifically, the paper examines the scriptural-prophetic argument the vizier makes about the likely existence of Chinese prophets, along with his use of Graeco-Islamic environmental-humoral theory to establish the benefits of translating Chinese medical knowledge. I focus on the way he uses the epistemological category of “experience” or “experiential knowledge” (tajriba) for Chinese (as well as Turkic and Mongol) medicine to “naturalize” Chinese-associated medical practice within an Islamic context, despite its apparent contradictions with Graeco-Islamic physiology and Galenic medical theory and imagery. I argue that tajriba is used to both defuse opposition to the engagement with Chinese medicine, while also relegating Chinese medicine to a subordinate position to Islamic “logic.” Rashid al-Din’s use of tajriba for Chinese medicine finds an interesting parallel in the seventeenth-century European project of translating Chinese medical recipes into Latin.