Jericho is in lock down for fear of the Israelites—no one gets in and no one gets outs.
God gives Joshua very specific instructions. The Israelite warriors must march around Jericho for six days with seven priests carrying trumpets made from rams's horns.
On the seventh day, the warriors should march seven times around the city blowing on the trumpets. When they make a long blast, then all the people should shout and the walls of the city will fall so Israel can charge forward (3-5).
Joshua gives these orders to the Israelites, making explicit instructions to make no sound for six days. In case you were wondering, we'd totally fail this assignment.
The Israelites do as God commands and march around Jericho for six days.
How tired were their legs? Super tired. But when God says march, you march.
On the seventh day before the siege, Joshua gives a rousing speech that is totally reminiscent of Aragorn's speech in Return of the King even though Tolkien wasn't even a glimmer in his mother's eye at this point.
Joshua tells the Israelites that they cannot harm Rahab or her family.
The Israelites must practice herem, meaning that they must destroy everything as a sacrifice to God and keep nothing for themselves… unless, of course, they want to bring destruction to their nation. Which they probably don't.