Numbers 10:7-9

Douay-Rheims 1899 American Edition

⁷ But when the people is to be gathered together, the sound of the trumpets shall be plain, and they shall not make a broken sound.

⁸ And the sons of Aaron the priest shall sound the trumpets: and this shall be an ordinance for ever in your generations.

⁹ If you go forth to war out of your land against the enemies that fight against you, you shall sound aloud with the trumpets, and there shall be a remembrance of you before the Lord your God, that you may be delivered out of the hands of your enemies.