Numbers 10:6-8

International Standard Version

⁶ When you sound the alarm the second time, those encamped on the south are to begin to travel. Alarms are to be sounded for their travels. ⁷ But when you blow the trumpet to assemble the whole congregation, don’t use the same sound as you do for sounding an alarm.^{[a] 8} The descendants of Aaron the priest are to blow the trumpets. Have them do this for you permanently throughout your generations to come.”