Numbers 10:7-9

New Living Translation

⁷ But when you call the people to an assembly, blow the trumpets with a different signal. ⁸ Only the priests, Aaron’s descendants, are allowed to blow the trumpets. This is a permanent law for you, to be observed from generation to generation.

⁹ “When you arrive in your own land and go to war against your enemies who attack you, sound the alarm with the trumpets. Then the Lord your God will remember you and rescue you from your enemies.