In this chapter, the nation of Israel is circumcised and Joshua meets the captain of the LORD's armies.
This chapter contains a number of interesting little anecdotes. First it tells us the kings of the Amorites and Canaanites are afraid because they've heard of the Israelites' crossing the Jordan. This was another one of the intended goals of splitting the Jordan. On a linguistic note, I have previously referred to the inhabitants of the promised land as "Canaanites", but more properly the Canaanites are only the collection of tribes or federated kingdoms that reside along the coastland (i.e. Gaza, Ashdod, Ashkelon, Gath and Ekron). Modern terminology (for instance, reading wikipedia) calls Canaan the entire land of ancient Israel plus Lebanon. For the sake of convenience, I am generally using the modern terminology, but the bible discusses the nations in Israel using more specific identities, such as verse 1 of this chapter.
Second, we learn that the Israelites had ceased performing circumcisions while they were traveling through the wilderness. In this same passage, we are told that the whole nation was circumcised while they were in Egypt. This is not actually described in the book of Exodus, but we can infer it happened probably before the Passover in Ex 12, because the ordinances of the Passover require that every male be circumcised (Ex 12:43-49). If not then, the second most likely place they were circumcised is at Sinai, during the time when Moses was given the Law.
Either way, the circumcision at Gilgal is another parallel between Joshua and the Pentateuch because in v. 2, the LORD says this is "the second time" they have performed a circumcision. This is strongly suggestive that it is a mass circumcision as an act of national dedication to the LORD, and saying it is the "second time" means that there was almost certainly a "first time" when they were in Egypt. Since the people were not circumcised in the wilderness, they probably also didn't observe the Passover in the wilderness. Their "reproach of Egypt" is because they haven't adhered to the commandments of the covenant in the most basic and significant ways, through circumcision and observance of the Passover. The LORD is bringing them back into alignment with the covenant before they enter the promised land.
Third, we are told that the people eat some of the food of the land and the same day, the manna stopped, coincidentally on the day of the Passover. This is very interesting and I think it reveals some important principles about how God operates. To wit, God gave the Israelites manna while they were in the wilderness. This taught the Israelites to depend upon him. Now the Israelites are moving from a land of barrenness to a land of plenty (cf. Num 13), so they no longer require manna. The provisions they possess change, but the challenges they face also change. In the wilderness, they fought few battles but they depended on the LORD to provide their daily bread. Now they have a natural source of food, but they will have to conquer towns and nations. Therefore the appearance of the LORD changes to suit their new needs. He is no longer the cloud by day and fire by night, now he appears as the great commander of the LORD's armies, as in vv. 13-15. And this is the fourth interesting story.
I've said on many occasions that the form of the appearance of the LORD is significant because the way that he appears is indicative of the message he is trying to convey. I have also said that Joshua is a book about the invasion of the promised land. The LORD's appearance in this chapter is a natural consequence of these two factors. The nation of Israel needs a military leader to guide them in battle, and that is how he now appears to Joshua.
But it's more significant than just that. He comes in the form of Israel's need and to fit their situation, but he does not come to serve Israel. As he replies in v. 14, he is not coming for Israel or their adversaries, he comes as captain of the LORD's armies. What that means is that he is fighting the LORD's battles and in service to the LORD. It is in fact forcing Joshua to choose if he will serve the LORD as well or serve his own purposes. As Joshua replies in v. 14, he will serve the LORD (by asking what his lord wishes of his servant, Joshua). This is another way of saying that Joshua wants to make himself and Israel part of the LORD's armies and to fight the LORD's battles.
Lastly, the LORD's command to Joshua in v. 15 is to remove his sandals, which is the exact same thing the LORD said to Moses in Ex 3:5, which is yet another parallel between the book of Joshua and the Pentateuch. I think it also exemplifies some other important differences between the experiences of Moses and Joshua, because Ex 3 was when the LORD first appeared to Moses. In that case, he appeared as a burning bush, granted Moses the power to do several miracles, and commanded him to lead the Israelites as they were brought out of Egypt to the promised land. Now that they are actually in the promised land and under the leadership of Joshua, the LORD appears now to Joshua as a military figure, placing upon him the demand of obedience.
This chapter is great because it really brings a lot of reconciliation between Israel and the LORD, Israel who had walked so far astray in her brief time outside of Egypt, failing to observe the rituals of the covenant, rebelling against the LORD so many times, sinning with the golden calf. Many of the differences have been smoothed over in this chapter... for now.