This work constitutes the critical edition and in-depth study of a unique dictionary of Biblical Hebrew written by Christian scholars at Ramsey Abbey in East Anglia, during the third quarter of the 13th century. Each of the Hebrew entries in the dictionary (over three thousand five hundred, alphabetically arranged) has been translated into Latin, as well as Old French (in more than a thousand cases) and also into Middle English (in three cases). These translations are illustrated by quotations from the Vulgate, which are in turn corrected according to the literal meaning of the Hebrew Bible or its Jewish interpretations. Rather than follow the patristic tradition of Hebraism and engage in anti-Jewish polemics, the Christian authors of this exceptional work actually turned to Jewish Rabbinic and Medieval sources, including the Aramaic targumim, midrashim, Rachi's commentaries, ibn Parhon's dictionary of Hebrew roots and so on. Building on the grammatical approach of the Spanish school, they elaborated a genuine philological work where the Hebrew Bible was used to correct the Vulgate, and more generally where the knowledge of the Hebrew language served to access and understand the original text of the Bible.