This volume introduces 'Ali b. 'Ubayda al-Rayhani (d. 219/834), one of the central figures in the transmission of classical Greek and Persian wisdom into Arabic. It offers an edition, translation, and evaluation of his book Jawahir al-kilam , one of the oldest collections of proverbial wisdom and moralia in Arabic, as well as other remaining pieces of his works. The first part of the book surveys the content of his more than sixty books and suggests that among his translations from Middle Persian into Arabic were the Sindbad-nama and Bilawhar wa-Budhasf. Moreover, he emerges as the author of the famous al-Adab al-saghir heretofore wrongly attributed to Ibn al-Muqaffa`. The second part contains the Arabic texts and translations as well as a rich documentation of their sources and their further transmission.