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. Make thee two trumpets of silver - The necessity of such instruments will at once appear, when the amazing extent of this numerous army is considered; and how even the sound of two trumpets could reach them all is difficult to conceive; but we may suppose that, when they were sounded, the motion of those that were within reach of that sound taught the others in succession what they should do.
As the trumpets were to be blown by the priests only, the sons of Aaron, there were only two, because there were only two such persons to use them at this time, Eleazar and Ithamar. In the time of Joshua there were seven trumpets used by the priests, but these were made, according to our text, of rams' horns, Joshua 6:4. In the time of Solomon, when the priests had greatly increased, there were 120 priests sounding with trumpets, 2 Chronicles 5:12.
Josephus intimates that one of these trumpets was always used to call the nobles together, the other to assemble the people; see Numbers 10:4. It is possible that these trumpets were made of different lengths and wideness, and consequently they would emit different tones. Thus the sound itself would at once show which was the summons for the congregation, and which for the princes only. These trumpets were allowed to be emblematical of the sound of the Gospel, and in this reference they appear to be frequently used. Of the fate of the trumpets of the sanctuary, See the note on Exodus 25:31.