This volume consists of a critical edition, English translation, and extensive introductory discussion of the Judaeo-Arabic commentaries on Ruth and Esther from the exegetical digest ( Kitāb al-bayān) of Tan ḥ um ben Joseph ha-Yerushalmi (d. 1291 CE), the last known exegete of the “rationalistic” school who wrote in Judaeo-Arabic. Although past scholarship has tended to regard Tan ḥ um’s exegetical contribution as little more than that of a compiler-abridger, our own assessment, as explored in the introduction, is that his role was in fact much more significant. Not only does he display the critical acumen and intellectual independence of a true exegete in his own right, but he also appears to have assimilated - and hence (like Abraham ibn Ezra) mediated into the continuum of Rabbanite exegesis - certain elements of Karaite exegesis, most notably, as developed by the tenth-century Karaite littérateur Yefet ben ‘ Eli, the role of the mudawwin in the composition and transmission of the biblical text.