Numbers 10:1

“And the Lord spake unto Moses, etc.] When the following directions concerning the trumpets were given is not certain; it may he at the time when the order of the camps of Israel was fixed, and is here recorded before the journeying of them, which was one use they were to be put unto, (<041002>Numbers 10:2); saying; as follows.”

“THE USE OF THE SILVER TRUMPETS. (Num. 10:1-36) Make thee two trumpets of silver--These trumpets were of a long form, in opposition to that of the Egyptian trumpets, with which the people were convened to the worship of Osiris and which were curved like rams' horns. Those which Moses made, as described by JOSEPHUS and represented on the arch of Titus, were straight, a cubit or more in length, the tubes of the thickness of a flute. Both extremities bore a close resemblance to those in use among us. They were of solid silver--so as, from the purity of the metal, to give a shrill, distinct sound; and there were two of them, probably because there were only two sons of Aaron; but at a later…”

“10:1-10 Israel needed signals that were loud and clear so that the tribes could receive instructions. Two silver trumpets provided a simple, effective means to signal all the tribes to move. • These trumpets were not the ram’s horns (Hebrew shopar) mentioned frequently in the Old Testament (e.g., Josh 6:4-6); they were fashioned by Israelite craftsmen from hammered silver brought out of Egypt.”

“The Silver Signal-Trumpets. - Although God Himself appointed the time for removal and encampment by the movement of the cloud of His presence, signals were also requisite for ordering and conducting the march of so numerous a body, by means of which Moses, as commander-in-chief, might make known his commands to the different divisions of the camp. To this end God directed him to prepare two silver trumpets of beaten work (mikshah, see Exo 25:18), which should serve "for the calling of the assembly, and for the breaking up of the camps," i.e., which were to be used for this purpose. The form of these trumpets is not further described. No doubt they were straight, not curved, as we may infer…”