Numbers 10:2-8

2“Make two trumpets of hammered silver to summon the community and have the camps set out.

3When both are sounded in long blasts, the entire community is to gather before you at the entrance to the tent of meeting.

4However, if one is sounded, only the leaders, the heads of Israel’s clans, are to gather before you.

5“When you sound short blasts, the camps pitched on the east are to set out.

6When you sound short blasts a second time, the camps pitched on the south are to set out. Short blasts are to be sounded for them to set out.

7When calling the assembly together, you are to sound long blasts, not short ones.

8The sons of Aaron, the priests, are to sound the trumpets. Your use of these is a permanent statute throughout your generations.