Numbers 10:10

7 But when the assembly is to be gathered together, you shall blow, but you shall not sound an alarm.

8 The sons of Aaron, the priests, shall blow the trumpets; and they shall be to you for a statute forever throughout your generations.

9 When you go to war in your land against the adversary who oppresses you, then you shall sound an alarm with the trumpets; and you shall be remembered before Yahweh your God, and you shall be saved from your enemies.

10 Also in the day of your gladness, and in your set feasts, and in the beginnings of your months, you shall blow 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 Yahweh your God.

11 It happened in the second year, in the second month, on the twentieth day of the month, that the cloud was taken up from over the tent of the testimony.

12 The children of Israel set forward according to their journeys out of the wilderness of Sinai; and the cloud abode in the wilderness of Paran.

13 They first took their journey according to the commandment of Yahweh by Moses.