NUMBERS 10:9-10

⁹And when ye go to war in your land against the adversary that oppresseth you, then ye shall sound an alarm with the trumpets; and ye shall be remembered before the LORD your God, and ye shall be saved from your enemies.

¹⁰Also in the day of your gladness, and in your set feasts, and in the beginnings of your months, ye shall blow with the trumpets over your burnt offerings, and over the sacrifices of your peace offerings; and they shall be to you for a memorial before your God: I am the LORD your God.