Joshua 6:2-6

But the LORD said to Joshua, “I have given you Jericho, its king, and all its strong warriors. You and your fighting men should march around the town once a day for six days. Seven priests will walk ahead of the Ark, each carrying a ram’s horn. On the seventh day you are to march around the town seven times, with the priests blowing the horns. When you hear the priests give one long blast on the rams’ horns, have all the people shout as loud as they can. Then the walls of the town will collapse, and the people can charge straight into the town.” So Joshua called together the priests and said, “Take up the Ark of the LORD’s Covenant, and assign seven priests to walk in front of it, each carrying a ram’s horn.”