Joshua 6:3-5
6:3 Have all the warriors march around the city one time; do this for six days.
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.”