Numbers 10:7-9

Amplified Bible, Classic Edition

⁷ When the congregation is to be assembled, you shall blow [the trumpets in short, sharp tones], but not the blast of an alarm.

⁸ And the sons of Aaron, the priests, shall blow the trumpets, and the trumpets shall be to you for a perpetual statute throughout your generations.

⁹ When you go to war in your land against the enemy that oppresses you, then blow an alarm with the trumpets, that you may be remembered before the Lord your God, and you shall be saved from your enemies.