Cross reference
Joshua 6:8
8 And it was so, that, when Joshua had spoken unto the people, the seven priests bearing the seven trumpets of rams' horns before Jehovah passed on, and blew the trumpets: and the ark of the covenant of Jehovah followed them.
Numbers 32:20
20 And Moses said unto them, If ye will do this thing, if ye will arm yourselves to go before Jehovah to the war,
Joshua 6:3-4
3 And ye shall compass the city, all the men of war, going about the city once. Thus shalt thou do six days.
4 And seven priests shall bear seven trumpets of rams' horns before the ark: and the seventh day ye shall compass the city seven times, and the priests shall blow the trumpets.