Commentaria in Deuteronomium
The whole Pentateuch was anciently, among the Hebrews, one single book of the law. Hence it is called in Hebrew Torah, and in Latin lex, the law, by Christ and the Evangelists; as in Luke, last chapter, verse 44: “All things must needs be fulfilled which are written in the law of Moses, and in the prophets”; and Luke ii, 23: “As it is written in the law of the Lord, that every male opening the womb shall be called holy to the Lord”; and, “to offer a sacrifice, according as it is written in the law of the Lord, a pair of turtledoves, or two young pigeons.”
Again, “What is written in the law? He answering said: Thou shalt love the Lord thy God with thy whole heart”; John i, 45: “Him of whom Moses in the law ... did write”; Matthew vii, 12: “This is the law and the prophets”; Matthew xxii, 36: “Which is the great commandment in the law?” There are like passages in Acts xxiv, 14, Acts xxvii, 23, and elsewhere.
Afterwards, however, the Pentateuch, according to the fivefold matter which it treats, was divided into five parts, or books. Hence this fifth section, or book, is called after its opening words, in the Hebrew manner, Elleh haddebarim, that is, “These are the words.” By the Greek interpreters, and first, as it seems, by the Septuagint, it was named Deuteronomy, that is, the second law, and by the Rabbis Mishneh, that is, the repetition of the law; not as though it contained a new law, different from the preceding ancient law, but because it is a repetition and explanation of the law given by God on Sinai thirty-eight years before, and described in the three books above, namely Exodus, Leviticus and Numbers. So Theodoret on this book, Question I, St. Augustine, Question XLIX, and Athanasius in his Synopsis of Holy Scripture. Hence St. Jerome in the Helmeted Prologue (which is prefixed like a helmet to all the books of Scripture): “Deuteronomy,” he says, “the second law, and the prefiguring of the Evangelical law, does it not so hold the things that went before, that yet all things become new out of the old?”
Moreover, this repetition of the law was made by Moses, when he was about to die, in the fortieth year after the departure from Egypt, a little before the Hebrews crossed the Jordan and entered Chanaan, in the plains of Moab, namely at Abelsatim, which was the forty-second and last encampment of the Hebrews in the desert.
The reason for the repetition was twofold. First, that all the old men who had come out of Egypt and had heard the first law on Sinai were now dead, on account of the murmuring of the spies, Numbers xiv; and the people then present were a new generation, who had not heard the former law promulgated. Hence in this second promulgation of the law God again made a new covenant with the Hebrews, as is said in chapter xxix, verse 4. The second reason was that Moses, being about to die, and to bid a last farewell to his own people and to the Hebrews committed to him, whom he loved more than his own life, wished by this repetition to impress the law upon them more deeply and more firmly. For the last words of parents, princes and teachers cling more firmly to children and subjects. Hence Deuteronomy is, as it were, a burning and perpetual discourse; and for that cause Moses, chapter xvii, verse 18, commanded that new kings, when chosen, should write out for themselves Deuteronomy, that they may learn, he says, to fear God. For the same cause, chapter xxxi, verse 10, he commanded that Deuteronomy should be read to the whole people in every seventh year of remission; nay, he commanded that it be inscribed on stones for an eternal memorial, Deut. xxvii.
The author of Deuteronomy, as of the whole Pentateuch, is Moses, who first promulgated it to the people by word of mouth, and then left it to them in writing, as is plain from Deuteronomy xxxi, 9: “Moses wrote this law, and delivered it to the priests.” Except, however, the last chapter, which was written not by Moses but by Esdras, or rather by Josue, the disciple and successor of Moses, as is plain from the same last chapter, verses 5 and 6, where the death and burial of Moses are described. For although Philo in the Life of Moses, and Josephus, Antiquities, book IV, last chapter, think that these things were written prophetically by Moses himself before his death, yet the contrary is truer, and this is signified both by other things and by those words: “And no man hath known his sepulchre until this present day”; which plainly must be understood of the time that followed his death.
Moses therefore spoke, and at the same time wrote, Deuteronomy in the 120th and last year of his life.