Biblical Commentary on the Old Testament, by Carl Friedrich Keil and Franz Delitzsh, [1857-78], at sacred-texts.com
After the distribution of the land by lot among the tribes of Israel, six towns were set apart, in accordance with the Mosaic instructions in Num 35, as places of refuge for unintentional manslayers. Before describing the appointment and setting apart of these towns, the writer repeats in Jos 20:1-6 the main points of the Mosaic law contained in Num 35:9-29 and Deu 19:1-13, with reference to the reception of the manslayers into these towns. לכם תּנוּ, "give to you," i.e., appoint for yourselves, "cities of refuge," etc. In Jos 20:6, the two regulations, "until he stand before the congregation for judgment," and "until the death of the high priest," are to be understood, in accordance with the clear explanation given in Num 35:24-25, as meaning that the manslayer was to live in the town till the congregation had pronounced judgment upon the matter, and either given him up to the avenger of blood as a wilful murderer, or taken him back to the city of refuge as an unintentional manslayer, in which case he was to remain there till the death of the existing high priest. For further particulars, see at Num 35.
List of the cites: Levitical cities were chosen, for the reasons explained in the Commentary on the Pentateuch.
In the land on this side (viz., Canaan) they sanctified the following cities. In the north, Kedesh (see at Jos 12:22), in Galil, on the mountains of Naphtali. Galil (a circle) was a district in the northern part of the subsequent province of Galilee; it is called הגּוים גּליל, circle of the heathen, in Isa 9:1, because an unusually large number of heathen or Gentiles were living there. In the centre of the land, Shechem, upon the mountains of Ephraim (see at Jos 17:7). And in the south, Kirjath-arba, i.e., Hebron, upon the mountains of Judah (see at Jos 10:3).
The cities in the land on the other side had already been appointed by Moses (Deu 4:41-43). For the sake of completeness, they are mentioned here again: viz., Bezer, Ramoth in Gilead, and Golan (see at Deu 4:43). The subject is brought to a close in Jos 20:9. המּוּעדה ערי signifies neither urbes congregationis (Kimchi) nor urbes asyli (Gesenius), but cities of appointment, - those which received the appointment already given and repeated again in what follows.