Joshua 6:1-5 NASB
1 Now Jericho was tightly shut because of the sons of Israel; no one went out and no one came in. 2The LORD said to Joshua, “See, I have given Jericho into your hand, with its king and the valiant warriors.
3 You shall march around the city, all the men of war circling the city once. You shall do so for six days. 4 Also seven priests shall carry seven trumpets of rams’ horn before the ark; then on the seventh day you shall march around the city seven times, and the priests shall blow the trumpets.
5 It shall be that when they make a long blast with the rams’ horn, and when you hear the sound of the trumpet, all the people shout with a great shout; and the wall of the city will fall down flat, and the people will go up every man straight ahead.”