Numbers 10:3-8

³And when they shall blow with them, all the assembly shall assemble themselves to thee at the door of the tabernacle of the congregation.

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

⁵When ye blow an alarm, then the camps that lie on the east parts shall go forward.

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

⁷But when the congregation is to be gathered together, 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.