Moreover the other functions assigned to the priests confirm the argument, and prove that in the time of Deuteronomy distinctions of rank among the Levites must have been firmly established. They had a place in the public justiciary, even in the supreme court, "in the place which Yahweh their God" had chosen (Deut. xvii. 9, xix. 17). Not only so, the law concerning a man found slain in chap. xxi., vv. 1-5, implies that there were in the cities throughout the land priests, the sons of Levi, whom "Yahweh thy God hath chosen to minister unto Him and to bless in the name of Yahweh, and according to their word shall every controversy and every stroke be." Now it cannot possibly have been the intention of the author of Deuteronomy that every member of the tribe of Levi should have equal power to decide such matters. If in his view every Levite was a priest, then we should have this impossible state of affairs, that the highest courts for judicial process should be in the hands of a class which was more largely indebted to the generosity of the rich for its maintenance than any other in the country. It seems plain therefore that every Levite could not exercise _full_ priestly functions because of his birth. Clearly, if any Levite might become a priest it was only in the same sense in which every Napoleonic soldier was said to carry a marshal's baton in his knapsack.[86] [86] The same conclusion must be come to in connection with the sanitary duties of the priesthood as laid down, or rather as alluded to, in Deut. xxiv. 8, 9. This implies that the Levitical priests had special duties in connection with such matters, duties which, if not precisely the same as those laid down in the Law of Leprosy (Lev. xiii., xiv.), must have nearly resembled them. Semi-medical skill must have been necessary for the satisfactory discharge of these duties, and we must suppose that the priests who discharged them were selected from the tribe of Levi on some principle either of special proved knowledge and fitness, or on the ground of hereditary devotion to such work. Finally, in this passage (ver. 5), by the words "him and his sons for ever," which refer back to "the priest," a hereditary character of the priesthood is asserted. This phrase is remarkably parallel to that so frequently used by P, "Aaron and his sons"; and though we are not told in what family or families the priesthood was hereditary, it must have been so in some. But in x. 6, 7, the family of Aaron is mentioned by the Deuteronomist as having hereditary right to the priesthood at the central shrine. There can therefore be no doubt that in the time of the author of Deuteronomy priesthood was hereditary, perhaps in several families, but certainly in the family of Aaron.