Numbers 10:2-8

2“Make two trumpets of silver; you are to make them from a single hammered piece. You will use them for assembling the community and for directing the traveling of the camps.

3When they blow them both, all the community must come to you to the entrance of the tent of meeting.

4“But if they blow with one trumpet, then the leaders, the heads of the thousands of Israel, must come to you.

5When you blow an alarm, then the camps that are located on the east side must begin to travel.

6And when you blow an alarm the second time, then the camps that are located on the south side must begin to travel. An alarm must be sounded for their journeys.

7But when you assemble the community, you must blow, but you must not sound an alarm.

8The sons of Aaron, the priests, must blow the trumpets; and they will be to you for an eternal ordinance throughout your generations.