[14] See further in exposition of chapter xvii; xviii.
The same conclusions follow when the regulations are examined which bear upon the support of the priestly tribe. The outstanding matters in this department are tithes and firstlings. Space will not admit of a full discussion of these topics; but if the reader will compare, in regard to tithes, Numb. xviii. 21-24 and Lev. xxvii. 30, 32, with Deut. xii. 17, and in regard to firstlings Numb. xviii. 18 with Deut. xii. 6, 17 f., and xv. 19 f., he will see that the application of tithes and of firstlings according to Deuteronomy is quite different from that in the Levitical legislation. The difference is such as will not comport with the hypothesis of a single legislator and a consistent legislation. Expedients with a view to solve the difficulty have been suggested by Keil and others; but each of those expedients is burdened with specific difficulties of its own.
The inevitable conclusion from all this would seem to be that in the Deuteronomic as in the Levitical laws we have not the legislation of Moses or of his age alone. The roots of all the legislative codes are Mosaic, but in all save perhaps the Book of the Covenant the trunk and branches are of much later growth. The authors of them are not careful to distinguish what came from Moses himself from that which had been developed out of it under the influence of the same inspiration. In both D and P there were Mosaic elements, and in both there are laws not given by him. To disentangle these completely now is impossible, and it is probably best for expository purposes to take the codes as giving what the Mosaic legislation had become at the time of the writer. What we have in Deuteronomy therefore cannot be better described than in Driver's words (_Introduction_, p. 85), as "the prophetic re-formulation and adaptation to new needs of an older legislation." Its relations to the other codes are as the same critic states (p. 71): "It is an _expansion_ of that in JE (Exod. xx.-xxiii.); it is, in several features, _parallel_ to that in Lev. xvii.-xxvi.; it contains _allusions_ to laws such as those codified in some parts of P, while from those contained in other parts of P it differs widely." And the state of things in which these various codes originated is more and more coming to be conceived in the manner stated by Dr. A. B. Davidson.[15] "It is evident," he says, "that two streams of thought, both issuing from a fountain as high up as the very origin of the nation, ran side by side down the whole history of the people, the prophetic and the priestly. In the one Jehovah is a moral ruler, a righteous king and judge, who punishes iniquity judicially or forgives sins freely of His mercy. In the other He is a Person dwelling among His people in a house, a Holy Being or Nature, sensitive to every uncleanness in all that is near Him, and requiring its removal by lustrations and atonement. Those cherishing the latter circle of conceptions might be as zealous for the Lord of Hosts as the prophets. And the developments of the national history would extend their conceptions and lead to the amplification of practices embodying them, just as they extended the conceptions of the prophets. A growth of priestly ideas is quite as probable as a growth of prophetic ideas. That the streams ran apart is no evidence that they were not equally ancient and always contemporaneous, for we see Jeremiah and Ezekiel both flourishing in one age. At one point in the history the prophetic stream was swelled by an inflow from the priestly, as is seen in Deuteronomy, and from the Restoration downwards both streams appear to coalesce."
[15] _Ezekiel_, Introduction, p. liv. f.