Numbers 10:6

3 When they shall blow them, all the congregation shall gather themselves to you at the door of the tent of meeting.

4 If they blow but one, then the princes, the heads of the thousands of Israel, shall gather themselves to you.

5 When you blow an alarm, the camps that lie on the east side shall take their journey.

6 When you blow an alarm the second time, the camps that lie on the south side shall take their journey: they shall blow an alarm for their journeys.

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.