The laws concerning the Cities of Refuge for Unintentional Manslayers are not a mere repetition of the laws given in Num 35:9-34, but rather an admonition to carry out those laws, with special reference to the future extension of the boundaries of the land.
As Moses had already set apart the cities of refuge for the land on the east of the Jordan (Deu 4:41.), he is speaking here simply of the land on the west, which Israel was to take possession of before long; and supplements the instructions in Num 35:14, with directions to maintain the roads to the cities of refuge which were to be set apart in Canaan itself, and to divide the land into three parts, viz., for the purpose of setting apart these cities, so that one city might be chosen for the purpose in every third of the land. For further remarks on this point, as well as with regard to the use of these cities (Deu 19:4-7), see at Num 35:11. - In Deu 19:8-10 there follow the fresh instructions, that if the Lord should extend the borders of Israel, according to His promise given to the patriarchs, and should give them the whole land from the Nile to the Euphrates, according to Gen 15:18, they were to add three other cities of refuge to these three, for the purpose of preventing the shedding of innocent blood. The three new cities of refuge cannot be the three appointed in Num 35:14 for the land on this side of the Jordan, nor the three mentioned in Num 35:7 on the other side of Jordan, as Knobel and others suppose. Nor can we adopt Hengstenberg's view, that the three new ones are the same as the three mentioned in Deu 19:2 and Deu 19:7, since they are expressly distinguished from “these three.” The meaning is altogether a different one. The circumstances supposed by Moses never existed, since the Israelites did not fulfil the conditions laid down in Deu 19:9, viz., that they should keep the law faithfully, and love the Lord their God (cf. Deu 4:6; Deu 6:5, etc.). The extension of the power of Israel to the Euphrates under David and Solomon, did not bring the land as far as this river into their actual possession, since the conquered kingdoms of Aram were still inhabited by the Aramaeans, who, though conquered, were only rendered tributary. And the Tyrians and Phoenicians, who belonged to the Canaanitish population, were not even attacked by David.
Innocent blood would be shed if the unintentional manslayer was not protected against the avenger of blood, by the erection of cities of refuge in every part of the land. If Israel neglected this duty, it would bring blood-guiltiness upon itself (“and so blood be upon thee”), because it had not done what was requisite to prevent the shedding of innocent blood.
But whatever care was to be taken by means of free cities to prevent the shedding of blood, the cities of refuge were not to be asyla for criminals who were deserving of death, nor to afford protection to those who had slain a neighbour out of hatred. If such murderers should flee to the free city, the elders (magistrates) of his own town were to fetch him out, and deliver him up to the avenger of blood, that he might die. The law laid down in Num 35:16-21 is here still more minutely defined; but this does not transfer to the elders the duty of instituting a judicial inquiry, and deciding the matter, as Riehm follows Vater and De Wette in maintaining, for the purpose of proving that there is a discrepancy between Deuteronomy and the previous legislation. They are simply commanded to perform the duty devolving upon them as magistrates and administrators of local affairs. (On Deu 19:13, see Deu 8:8 and Deu 8:5.)