DEUT. xviii. 1-8
The priesthood naturally follows the kingship in the regulations regarding the position of the governing classes. But it was an older and much more radical constituent in the polity of Israel than we have seen the kingship to be. Originally, the priests were the normal and regular exponents of Yahweh's will. They received and gave forth to the people oracles from Him, and they were the fountain of moral and spiritual guidance. The Torah of the priests, which on the older view was the Pentateuch as we have it, or its substance at least, which Moses had put into their hands, is much more probably now regarded as the guidance given by means of the sacred lot and the Urim and Thummim. Because of their special nearness to and intimacy with God, the priests were in contact with the Divine will and could receive special Divine guidance; and in days when the voice of prophecy was dumb, or in matters which it left untouched, the priestly Torah, or direction, was the one authorised Divine voice. But this was not the only function of the priests. Sacrificial worship was a more fundamental function. Wellhausen and his school indeed seem inclined to deny that as priests of Yahweh they had any Divinely ordered connection with sacrifice. But the truer view is that their power to give Torah to Israel depended entirely upon their being the custodians of the places where Yahweh had caused His name to be remembered. The theory was that, as they approached Him with sacrifices in His sanctuaries, they consequently could speak for Him; so that the guarding of His shrines, and the offering of the people's sacrifices there were their first duties. In fact they were the mediators between Yahweh and Israel. Yahweh was King, but He was invisible, and the priests were His visible earthly representatives. The dues, which in a merely secular state would have gone to the king, as rent for the lands held of him, were employed for their appointed uses by the priests, as the servants and representatives of the heavenly King who had bestowed the land upon Israel and allotted to each family its portion. Occupying a middle position, then, between the two parties to the Covenant by which Israel had become Yahweh's chosen people, they spoke for the people when they appeared before Yahweh, and for Him when they came forth to the people. They were, as we have said, the oldest and most important of the ruling classes, and must have been from early times a special order set apart for the service of Israel's God.
The main passages in Deuteronomy which bear upon the position and character of the priesthood and of the tribe of Levi are the following. In chaps. xviii. 1-8, x. 6-9, and xxvii. 9-14 the strictly priestly functions of the tribe of Levi are dealt with; in xvii. 9 ff. xix. 17, the judicial functions; in xxi. 1-5 their function in connection with sanitary matters is referred to. Besides these there are the various injunctions to invite the Levites to the sacrificial feasts, because they have no inheritance, and a number of references to the priesthood as a well-known body, the constitution and duties of which did not need special treatment. These last are of themselves sufficient to prove beyond question that in dealing with the priests and Levites the author of this book writes from out of the midst of a long established system. He does not legislate for the introduction of priests, neither does he refer to a priestly system recently elaborated by himself, and only now coming into operation. He does not tell us how priests are to be appointed, nor from whom, nor with what ceremonies of consecration they are to be inducted into their office. In fact the writer speaks of what concerns the priests and Levites in a manner which makes it certain that in his day there were, and had long been, Levites who were priests, and Levites of whom it may at least be said that they were probably nothing more than subordinates in regard to religious duty. In a word, while presupposing an established system of priestly and Levitical service, he nowhere attempts to give any clear or complete view of that system. His whole mind is turned towards the people. It is about their duties and their rights he is anxious, about their duties perhaps more than their rights; and he touches upon matters connected with others than the people only in a cursory way. In this matter, especially, he clearly needs to be supplemented by information drawn from other sources, and his every word about it shows that he is not introducing or referring to anything new. Any modifications he makes are plainly stated and are limited to a few special points.