2. 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 period the number was greatly increased (Jos 6:8; 2Ch 5:12). And although the camp comprehended 2,500,000 of people, two trumpets would be quite sufficient, for sound is conveyed easily through the pure atmosphere and reverberated strongly among the valleys of the Sinaitic hills.

     3-7. when they shall blow with them—There seem to have been signals made by a difference in the loudness and variety in the notes, suited for different occasions, and which the Israelites learned to distinguish. A simple uniform sound by both trumpets summoned a general assembly of the people; the blast of a single trumpet convoked the princes to consult on public affairs; notes of some other kind were made to sound an alarm, whether for journeying or for war. One alarm was the recognized signal for the eastern division of the camp (the tribes of Judah, Issachar, and Zebulun) to march; two alarms gave the signal for the southern to move; and, though it is not in our present Hebrew text, the Septuagint has, that on three alarms being sounded, those on the west; while on four blasts, those on the north decamped. Thus the greatest order and discipline were established in the Israelitish camp—no military march could be better regulated.

     8. the sons of Aaron the priests shall blow with the trumpets, &c.—Neither the Levites nor any in the common ranks of the people could be employed in this office of signal giving. In order to attract greater attention and more faithful observance, it was reserved to the priests alone, as the Lord's ministers; and as anciently in Persia and other Eastern countries the alarm trumpets were sounded from the tent of the sovereign, so were they blown from the tabernacle, the visible residence of Israel's King.

     9. If ye go to war—In the land of Canaan, either when attacked by foreign invaders or when they went to take possession according to the divine promise, "ye [that is, the priests] shall blow an alarm." This advice was accordingly acted upon (Nu 31:6; 2Ch 13:12); and in the circumstances it was an act of devout confidence in God. A solemn and religious act on the eve of a battle has often animated the hearts of those who felt they were engaged in a good and just cause; and so the blowing of the trumpet, being an ordinance of God, produced that effect on the minds of the Israelites. But more is meant by the words—namely, that God would, as it were, be aroused by the trumpet to bless with His presence and aid.

     10. Also in the day of your gladness, and in your solemn days—Festive and thanksgiving occasions were to be ushered in with the trumpets, as all feasts afterwards were (Ps 81:3; 2Ch 29:27) to intimate the joyous and delighted feelings with which they engaged in the service of God.

     8. The arrival of the enemy is announced in the form of an injunction to blow an alarm.

     6. When the sound of alarm is trumpeted by the watchman in the city, the people are sure to run to and fro in alarm (Hebrew, literally). Yet Israel is not alarmed, though God threatens judgments.