Those great verses, Deut. vi. 4, 5, form the central truth of the book. Everything else in it proceeds from and is informed by them, and they are dwelt upon and enforced with a clear perception of their radical importance. There is something of the joy of discovery in the way in which the unity of Yahweh and exclusive love to Him are insisted upon, not only in verses 6-25 of this chapter, but in xi. 13-20. The same strongly worded demand to lay to heart Yahweh's command to love Him and Him only, and to teach it strenuously to their children--to make it "a sign upon their hand," and "as a frontlet between their eyes"--is found in both passages. It is worthy of remark also that nearly the same words are found in Exod. xiii. 9, 16. Presumably on account of this, some have ascribed that section of Exodus to the author of Deuteronomy. But both Dillmann and Driver ascribe these passages to J and E, and with good reason. Indeed, apart from the purely literary grounds for thinking that these formulas were first used by the earlier writers and were copied by the author of Deuteronomy, another line of argument points in the same direction. In Exodus the thing to be remembered and taught to the children was the meaning and origin of the Passover and the consecration of the firstborn, _i.e._ the meaning and origin of some of their ritual institutions. Here in Deuteronomy, on the contrary, that which is to be written on the heart and taught to the children is moral and spiritual truth about God, and love to God. Now the probable explanation of this likeness and difference is, not that the author of Deuteronomy, after using this insistive phrase only of high spiritual truths in his own book, inserted it in Exodus with regard to mere institutions of the cultus; rather, the writers of Exodus had used it of that which was important in their day, and the Deuteronomist borrowed it from them to emphasise his own most cherished revelation. In the earlier stages of a religious movement, the establishment of institutions which shall embody and perpetuate religious truth, is one of the first necessities. It has become a commonplace of Christian defence, for example, that Baptism and the Lord's Supper were made the most successful vehicles for conveying fundamental Christian truth, and that the celebration of these two rites from the first days even until now is one of the most convincing proofs of the continuity of Christianity. Naturally, therefore, the establishment of the Passover was specially marked out as the _palladium_ of Israelite religion in the earlier days. But in the time after Isaiah, when Deuteronomy was written, the institutions needed no longer such insistence. They had indeed become so important to the people that the mere observance of them threatened to become a substitute for religious and even moral feeling. The Deuteronomist's great message was, consequently, a reiteration of the prophetic truths as to the supremacy of the