Joshua 6:8-10

8And it was so, that when Joshua had spoken to the people, the seven priests carrying the seven trumpets of rams’ horns before the Lord went forward and blew the trumpets; and the ark of the covenant of the Lord followed them.

9And the armed men went ahead of the priests who blew the trumpets, and 1the rear guard came after the ark, while they continued to blow the trumpets.

10But Joshua commanded the people, saying, “You shall not shout nor let your voice be heard, nor let a word proceed from your mouth, until the day I tell you, ‘Shout!’ Then you shall shout!”