Joshua 6:8, 13

So it was, when Joshua had spoken to the people, that the seven priests bearing the seven trumpets of rams’ horns before the LORD advanced and blew the trumpets, and the ark of the covenant of the LORD followed them.

Then seven priests bearing seven trumpets of rams’ horns before the ark of the LORD went on continually and blew with the trumpets. And the armed men went before them. But the rear guard came after the ark of the LORD, while the priests continued blowing the trumpets.