John Gill's Bible Commentary Ver. 4. And if they blow [but] with one [trumpet] , etc.] With only one of them, or but once, with one sounding, and that an even one as before: then the princes, [which are] the heads of the thousands of Israel , shall gather themselves unto thee : and they only or alone, as Aben Ezra: by this token, or by this difference of blowing both trumpets, or only one, it was, easily known when the whole congregation or when the princes only were to meet Moses at the same place, the door of the tabernacle of the congregation; and all are to attend divine service, and the ministry of the word, even the whole church of God, and all the members of it, high and low, rich and poor, princes and people.
Matthew Henry Commentary
Verses 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 typif the preached gospel. It sounds an alarm to sinners, calls them to repent, proclaims liberty to the captives and slaves of Satan, an 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 distinct sound, according to the persons addressed, or the en 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. (Nu 10:11-28)
Original Hebrew ואם518 באחת259 יתקעו8628 ונועדו3259 אליך413 הנשׂיאים5387 ראשׁי7218 אלפי505 ישׂראל׃3478