"1 Now the gates of Jericho were securely barred because of the Israelites. No one went out and no one came in. 2 Then the LORD said to Joshua, “See, I have delivered Jericho into your hands, along with its king and its fighting men. 3 March around the city once with all the armed men. Do this for six days. 4 Have seven priests carry trumpets of rams’ horns in front of the ark. On the seventh day, march around the city seven times, with the priests blowing the trumpets. 5 When you hear them sound a long blast on the trumpets, have the whole army give a loud shout; then the wall of the city will collapse and the army will go up, everyone straight in.”
6 So Joshua son of Nun called the priests and said to them, “Take up the ark of the covenant of the LORD and have seven priests carry trumpets in front of it.” Joshua 6:1-6
The Lord gave Joshua specific instructions about taking over the city of Jericho. He told them to march around the wall for seven days. For six days they marched around the city once. But on the seventh day, they were to walk around 7 times, the trumpet was to be blown, and they were to give a loud shout. This would cause the wall to fall down.