Numbers 10:7-9

Young's Literal Translation

⁷ `And in the assembling of the assembly ye blow, and do not shout;

⁸ and sons of Aaron, the priests, blow with the trumpets; and they have been to you for a statute age-during to your generations.

⁹ `And when ye go into battle in your land against the adversary who is distressing you, then ye have shouted with the trumpets, and ye have been remembered before Jehovah your God, and ye have been saved from your enemies.