Shared ground
Joshua 20:1–2 presents the start of a community-level policy in Israel’s life in the land. The text is explicit that the initiative comes from Yahweh: he speaks to Joshua, and Joshua is then to speak to “the children of Israel.” The passage also explicitly links the command to earlier instruction given through Moses, so this is framed as implementing a standing directive rather than creating something new.
Even though these two verses do not explain the system yet, they clearly set up an ordered chain of authority (Yahweh → Joshua → Israel) and prepare the reader for the naming and function of the refuge cities in the verses that follow.
Where interpretation differs
What “assign/designate” involves. Some read the verb as mainly “name/select the cities,” since the next section lists the specific towns. Others think it also implies practical preparation (public recognition, access, procedures), because “cities of refuge” only work if the community treats them as such.
Who is addressed by “children of Israel.” Some take it as the whole population in a general sense. Others hear a more practical focus on the tribes and leaders who would carry out the designation, since organizing cities would require coordinated decisions.
Why the disagreement exists
Verse 2 gives the command but not the implementation details. The larger chapter supplies names and purpose, and the Torah passages supply broader instructions (e.g., Numbers 35:9–15; Deuteronomy 19:1–3). Readers weigh how much of that background should be assumed here versus treated as belonging mainly to later verses.
What this passage clearly contributes
Joshua 20:1–2 establishes (1) divine authorization for the refuge-city system, (2) continuity with Moses’ earlier instruction, and (3) that this is a public, Israel-wide action rather than a private arrangement. It also signals a shift from conquest narratives to sustaining communal order in the land, where preventing uncontrolled revenge after a death will matter for Israel’s stability.