Joshua 6:4-6

6:4 Have seven priests carry seven rams’ horns in front of the ark. On the seventh day march around the city seven times, while the priests blow the horns. 6:5 When you hear the signal from the ram’s horn, have the whole army give a loud battle cry. Then the city wall will collapse and the warriors should charge straight ahead.”

6:6 So Joshua son of Nun summoned the priests and instructed them, “Pick up the ark of the covenant, and seven priests must carry seven rams’ horns in front of the ark of the Lord.”

Joshua 6:13-15

6:13 The seven priests carrying the seven rams’ horns before the ark of the Lord marched along blowing their horns. Armed troops marched ahead of them, while the rear guard followed along behind the ark of the Lord blowing rams’ horns. 6:14 They marched around the city one time on the second day, then returned to the camp. They did this six days in all.

6:15 On the seventh day they were up at the crack of dawn and marched around the city as before – only this time they marched around it seven times.