In this chapter, the author recounts the journey of Israel from Egypt to their camp on the east bank of the Jordan, opposite Jericho.
This chapter is basically the end of the Numbers story. There are three chapters that follow, but they are more of an appendix than anything else, covering a few miscellaneous topics related to the division of the land.
The structure of this chapter also shows that it is a conclusion of sorts, as we metaphorically walk through the journey from its beginning in Egypt to its end (so far) on the borders of the promised land, east of the Jordan. We really have gone quite a ways, both the Israelites in the story and you, the readers of this commentary. We began this journey two books ago when the Israelites were suddenly and precipitously dropped into freedom, sent wandering through the Middle Eastern desert in search of a home. Back then Moses was incredibly insecure and reluctant to lead the Israelites. We have seen him grow tremendously as he is now a very authoritative figure. Back then the Israelites were rebellious, worshiped other gods and sought to return to slavery in Egypt. I guess not everything has changed.
The Israelites started their journey with the first Passover, which we read about in Ex 12. Many of the names in the journey should be familiar to us: they started out in Rameses (Ex 12:37), journeyed through Succoth (Ex 12:37) and turned back to Pi-hahiroth (Ex 14:2). Then they passed through the sea (Ex 14:22), camped at Marah (Ex 15:23) and Elim (Ex 15:27). They journeyed to Rephidim (Ex 17:1) where they fought the Amalekites. From there they travel to Kibroth-hattaavah, the "graves of longing" where the people died from their lust (Num 11:34), and went on to Hazeroth (Num 11:35).
Then there's a long series of names we have never seen before, before the people reach Kadesh (Num 20:1). Aaron dies and the people march on through a few more obscure campsites before reaching Moab and the Jordan.
Overall, I think this chapter is kinda like a genealogy. It contains a list of dozens of obscure names (like Rissah or Kehelathah) that never appear before or after in the bible, or even non-biblical sources. Generally, the majority of these sites have not, and cannot, be positively identified because there is simply no other material that cross-references their locations. The reason why I think this is like a genealogy is that it is a long list of obscure names that is usually of profound interest to scholars and linguists, while of little interest or significance to people like us who are reading the bible for personal study.
As a result, I don't think there's much in this chapter worth discussing. Some of the names can be cross-referenced to various stories (like what I did above), but rather than teach us anything new, this chapter is really just a reminder of the past and should be a time of reflection.
Verse 50 breaks off from the "journeys of the sons of Israel" and gives us the command that all the inhabitants of Canaan must be killed, their idolatrous religions destroyed, and the land distributed by lot.
I will start with a minor point and then move on to the more interesting subject. The discussion of inheriting the land by lot is similar to Num 26:52-56, which similarly divided the land by lot, according to the "number of names". We can imagine the land will be divided both into tribes by size, but within each tribe individual clans would receive land by the number of names, and within each clan individual families would receive land by the number of names. So it is a hierarchical breakdown that is scaled by the number of people in each unit, but then randomized (drawn by lot) to ensure that everyone is treated equally.
Moving on to the more significant point, I think this is the first time the Israelites have been commanded to destroy the Canaanites, but for various reasons we could have seen it coming. For one, God said that the descendants of Abraham would not return to Canaan until the fourth generation because the "sin of the Amorite is not yet complete" (Gen 15:16). This means that the return of the Israelites is a means of punishment for the sins of the "Amorite", i.e. the inhabitants of Canaan.
For another, we have seen numerous battles as the Israelites head towards Canaan, starting with the Amalekites in Ex 17 and continuing with the two Amorite kings in Num 21 and the Midianites more recently in Num 31. Also, the LORD deliberately took the Israelites through the desert, rather than the more populous coastal road, because "the people might change their minds when they see war, and return to Egypt" (Ex 13:17). I discussed on several occasions the militaristic language of Numbers itself, such as the military census of Num 1 and the trumpets of Num 10. All of these things show a heightened expectation of warfare.
So while this is the first time we are told the Canaanites must be exterminated completely, it shouldn't entirely surprise us. After all, the Midianites were effectively exterminated when the Israelites slew all their males. The risk of leaving any Canaanites alive is presented here as well: "they will trouble you in the land in which you live" (v. 55), because of the exact same reason as the Midianites: the idolatry of the natives would guide the Israelites into a syncretic idolatry of their own. This should also not surprise us, because the Israelites have struggled with syncretic idolatry for nearly their whole history, starting definitively with the golden calf of Ex 32, but probably while in Egypt too (it is very likely the Israelites worshiped Egyptian gods while in slavery).
Killing all the natives is a matter of survival for the Israelites. If they do not, and get ensnared in the "sin of the Amorite", then the Israelites must be punished in the exact same way that "the Amorite" would be punished. "As I plan to do to them, so I will do to you" (v. 56). This risk is emphasized in verses 52-53, which discuss the inhabitants' many "figured stones", "molten images" and "high places", the many centers of idolatrous worship. The LORD used similar terms in Lev 26 when he threatened the Israelites will grim destruction if they "do not obey me and do not carry out all these commandments". In that chapter he spoke of destroying the Israelites' "high places", "incense altars", and "idols", which are symbols of their adoption of Canaanite worship. That chapter is a very detailed description of what the Israelites will suffer if they do not destroy the Canaanites.
This leads us to roughly two conclusions. First, the native inhabitants will definitely fight back against the Israelites, as the limited resources of the land force an inevitable conflict between the invading Israelites and the local Canaanites. This isn't so much a battle for land to live in as it's a battle over the scarce resources, soil, grass and water, of this semi-arid region. The Israelites have prepared for this conflict and at this point it seems unavoidable.
However, just because a conflict is inevitable, and presuming an Israelite victory, doesn't mean that the Canaanites will be wiped out completely. It is possible that only some of the Canaanites will be killed, with the rest either maintaining their territory or integrating into Israelite society (whether through marriage or slavery). This is what the LORD is warning against.
Second, any surviving Canaanites will "infect" the Israelites with idolatry and turn people away from the LORD. We know the Canaanites worship idols and we know that the Israelites have a strong tendency to also worship idols, even without other people to encourage them. We also know that the Moabites led the Israelites into idolatry earlier in Num 25, which is exactly the risk as they move into Canaan. If the Israelites allow this to happen then they will lose their sovereign protection through the covenant and furthermore, incur the wrath of the LORD, as they were warned in Lev 26.