Chapters 6-12 describe the defeat of the Canaanite peoples.
v1: The people of Jericho remained closed; the people feared Israel. But there was no message of peace, for they remained opposed to Israel. Nor were there deserters.
v2: Victory was certain. This had been promised for many months. Now the promises of God would be fulfilled.
v3-5: God's strategy was to have His people march around the city. This may have seemed foolish to man; our part is to believe and obey, not to question and argue.
v6-14: For six days, the people of Jericho watched the spectacle of many thousands of people marching around the city, silent except for the blowing of trumpets.
v15-16: On the seventh day, the people marched around seven times, and then shouted out in victory, as instructed in v10.
v17-19: Jericho was the first city to be taken. It was therefore 'devoted to God.' This meant that everything was for Him, every living thing had to be killed (v23), and all materials of value were to be consecrated to Him. There was nothing for the Israelites. This itself was a test of obedience, as the people were fighting for Him. They had to learn to put God first; this is consistent with the unusual strategy for defeating the city.
Here too was a warning for the other Canaanite cities; a warning for the Israelites, to keep away from "the devoted things"; a lesson for us, to learn to think how God thinks.
v20: There was a long blast on the trumpets (ram's horns), see v5; this was presumably louder than the daily blowing of the trumpets.
v25: Rahab and her family were preserved, as the spies had promised. She was rewarded by her loyalty to the people of God; both Jethro (Ex 18), and Ruth (Ruth 1.16) were similarly rewarded. Although Israel was clearly God's chosen, any individual from any other people could join with them in true faith. The word transated 'lived' or 'dwelt' means 'in the bowels of.' In other words, Rahab became absorbed within the heart and life of the nation of Israel; much like Ruth who later strongly identified with the nation of Naomi.
v26: Since the city was given over to the Lord, it was not to be rebuilt. Joshua pronounced a curse upon anyone who sought to rebuild it. In 1 Kings 16.34, Hiel of Bethel rebuilt it, and the curses were fulfilled.
v27: The Lord’s blessing fell on Joshua, as leader of the people, see 4.14; and also throughout the land, as news of the defeat of Jericho spread.