Numbers 10:8-9

10:8 The sons of Aaron, the priests, must blow the trumpets; and they will be to you for an eternal ordinance throughout your generations. 10:9 If you go to war in your land against an adversary who opposes you, then you must sound an alarm with the trumpets, and you will be remembered before the Lord your God, and you will be saved from your enemies.

Numbers 31:6

Campaign Against the Midianites

31:6 So Moses sent them to the war, one thousand from every tribe, with Phinehas son of Eleazar the priest, who was in charge of the holy articles and the signal trumpets.

Joshua 6:13-20

6:13 The seven priests carrying the seven rams’ horns before the ark of the Lord marched along blowing their horns. Armed troops marched ahead of them, while the rear guard followed along behind the ark of the Lord blowing rams’ horns. 6:14 They marched around the city one time on the second day, then returned to the camp. They did this six days in all.

6:15 On the seventh day they were up at the crack of dawn and marched around the city as before – only this time they marched around it seven times. 6:16 The seventh time around, the priests blew the rams’ horns and Joshua told the army, “Give the battle cry, for the Lord is handing the city over to you! 6:17 The city and all that is in it must be set apart for the Lord, except for Rahab the prostitute and all who are with her in her house, because she hid the spies we sent. 6:18 But be careful when you are setting apart the riches for the Lord. If you take any of it, you will make the Israelite camp subject to annihilation and cause a disaster. 6:19 All the silver and gold, as well as bronze and iron items, belong to the Lord. They must go into the Lord’s treasury.”

6:20 The rams’ horns sounded and when the army heard the signal, they gave a loud battle cry. The wall collapsed and the warriors charged straight ahead into the city and captured it.