Joshua 6:8-10

8And it came to pass when Joshua had spoken to the people, that the seven priests carrying the seven blast-trumpets before Jehovah passed on and blew with the trumpets; and the ark of the covenant of Jehovah went after them.

9And the armed men went before the priests who blew with the trumpets, and the rearguard came after the ark; they blew with the trumpets in marching.

10And Joshua had commanded the people, saying, Ye shall not shout, nor let your voice be heard, neither shall a word proceed out of your mouth, until the day I say to you, Shout; then shall ye shout.