10:1-10 Here are directions concerning the public notices to be given the people by sound of trumpet. Their laws in every case were to be Divine, therefore, even in this matter Moses is directed. These trumpets typify the preached gospel. It sounds an alarm to sinners, calls them to repent, proclaims liberty to the captives and slaves of Satan, and collects the worshippers of God. It directs and encourages their heavenly journey; stirs them up to combat against the world and sin, encouraging them with the assurance of victory. It leads their attention to the sacrifice of Christ, and shows the Lord's presence for their protection. It is also necessary that the gospel trumpet give a distinct sound, according to the persons addressed, or the end proposed; whether to convince, humble, console, exhort, reprove, or teach. The sounding of the trumpet of the gospel is God's ordinance, and demands the attention of all to whom it is sent.
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.