Here is a proposal based on the principle of 1 Corinthians 14:8 -9, “For if the trumpet give an uncertain sound, who shall prepare himself to the battle? 9 So likewise ye, except ye utter by the tongue words easy to be understood, how shall it be known what is spoken? for ye shall speak into the air.” The trumpets themselves are only mentioned in verses 2,8,9,10. Israel needed to distingusish the sound of one versus two trumpets, and between a regular blast and an alarm, and also note the number of alarms. The signals fall into two purposes – to call the assembly together and to move forward in battle formation. When two trumpets sound a long blast then the whole congregation comes together, when only one, the princes come on their own. Short repeated blasts (an alarm) signals the camp moves forward, or in time of war, it is a call for YHWH to fight for them. (Even when the camp moved forward on their journey Moses said, “Rise up, LORD, and let thine enemies be scattered; and let them that hate thee flee before thee” (v35). In time of peace the trumpets would sound out the solemn days and the beginning of a new month.
A. 1 And the LORD spake unto Moses, saying, 2 Make thee two trumpets of silver; of a whole piece shalt thou make them: that thou mayest use them for the calling of the assembly, and for the journeying of the camps.
B. Blow long blasts
3 And when they shall blow with them, all the assembly shall assemble themselves to thee at the door of the tabernacle of the congregation. 4 And if they blow but with one trumpet, then the princes, which are heads of the thousands of Israel, shall gather themselves unto thee.
C. Blow short blasts
5 When ye blow an alarm, then the camps that lie on the east parts shall go forward. 6 When 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. 7 But when the congregation is to be gathered together, ye shall blow, but ye shall not sound an alarm.
A’. 8 And 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.
C’. Blow short blasts
9 And if ye go to war in your land against the enemy that oppresseth you, then ye shall blow an alarm with the trumpets; and ye shall be remembered before the LORD your God, and ye shall be saved from your enemies.
B’. Blow long blasts
10 Also in the day of your gladness, and in your solemn days, and in the beginnings of your months, ye shall blow with the trumpets over your burnt offerings, and over the sacrifices of your peace offerings; that they may be to you for a memorial before your God: I am the LORD your God.