Joshua 6:8, 13

And 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.

The seven priests carrying the seven trumpets of rams’ horns before the ark of the LORD went on continually, and blew the trumpets; and the armed men went before them and the rear guard came after the ark of the LORD, while they continued to blow the trumpets.