Numbers 10:2-8

2“Make two trumpets of silver; you shall make them of hammered work. You shall use them to summon the congregation and to have the camps move out.

3When both are blown, all the congregation [that is, all adult males] shall gather before you at the doorway of the Tent of Meeting (tabernacle).

4However, if a single trumpet is blown, then the leaders, heads of the tribes of Israel, shall gather themselves to you.

5When you blow an alarm, the camps on the east side [of the tabernacle] shall set out.

6When you blow an alarm the second time, then the camps on the south side [of the tabernacle] shall set out. They shall blow an alarm whenever they are to move out [on their journeys].

7When the assembly is to be gathered, you shall blow [the trumpets in short, sharp tones], but without sounding an alarm.

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