Numbers 10:3-8

³And when they shall blow with both, all the congregation shall assemble themselves unto thee at the door of the tabernacle of the congregation.

⁴And if they blow with but one, then shall assemble themselves unto thee the princes, the heads of the thousands of Israel.

⁵And when ye blow an alarm, then shall set forward the camps that encamp on the east side.

⁶And when ye blow an alarm the second time, then shall set forward the camps that encamp on the south side: an alarm shall they blow for their setting forward.

⁷But at the assembling of the assembly, ye shall blow, but ye shall not sound an alarm.

⁸And the sons of Aaron, the priests, shall blow with the trumpets; and they shall be to you for an ordinance for ever throughout your generations.