God commands, 1-6, and the children of Israel appoint the six cities of refuge, 7-9.
1 The LORD also spoke to Joshua, saying, 2 "Speak to the children of Israel, saying, 'Appoint for yourselves cities of refuge, of which I spoke to you by the hand of Moses, 3 So that the slayer who kills any person unintentionally and ignorantly may flee there. And they shall be your refuge from the avenger of blood. 4 And when he who flees to one of those cities stands at the entering of the gate of the city and declares his cause in the ears of the elders of that city, they shall take him into the city to them and give him a place so that he may dwell among them. 5 And if the avenger of blood pursues him, then they shall not deliver the slayer into his hand because he smote his neighbor ignorantly and had not hated him before. 6 And he shall dwell in that city until he stands before the congregation for judgment and until the death of the high-priest who shall be in those days. Then the slayer shall return, and come to his own city and to his own house, to the city from where he fled.'"
7 And they appointed Kedesh in Galilee in the mountains of Naphtali, Shechem in the mountains of Ephraim, and Kirjath-arba (which is Hebron) in the mountains of Judah. 8 And on the other side of the Jordan by Jericho eastward, they assigned Bezer in the wilderness upon the plain out of the tribe of Reuben, Ramoth in Gilead out of the tribe of Gad, and Golan in Bashan out of the tribe of Manasseh. 9 These were the cities appointed for all the children of Israel and for the stranger sojourning among them, so that whoever kills any person unintentionally might flee there and not die by the hand of the avenger of blood until he stood before the congregation.
Matthew Henry Commentary - Joshua, Chapter 20[➚]
[v.2] - "cities of refuge" - Reference, Numbers 35:6-15.