Within these pages is presented for the first time a critical edition of the Commentary to chapters II -X of Genesis of Immanuel ben Solomon of Rome. (Chapter I was edited and published during the preparation of this thesis by Franco Michelini Tocci, Roma, 1963). The edition is based on two manuscripts: one from the library of the Jewish Theological Seminary, New York, and the other from the Biblioteca Paletina di Parma. The text is accompanied with a critical apparatus showing the differences between the two manuscripts. Comprehensive notes are added which attempt to trace Immanuel's sources, elucidate the form and background of philosophical and scientific approach to the Bible, and place him in the history of medieval Jewish exegesis. English translations of the more difficult passages are appended, and a brief summary of the major elements in the text is given. The Introduction gives for the first time a full list of all the manuscripts of Immanuel's commentaries to the Bible, and a critical estimate is attempted of Immanuel's use of his source material. The whole provides an insight in the growth of philosophical Bible commentary, and throws light On the mental outlook of one of the great leaders of the Rome Jewish community in the Middle Ages.