Moses
Numbers 10:3ESV·traditional attribution

And when both are blown, all the congregation shall gather themselves to you at the entrance of the tent of meeting.

Matthew Henry Presbyterian @wholebiblehenry

We have here directions concerning the public notices that were to be given to the people upon several occasions by sound of trumpet. In a thing of this nature, one would think, Moses needed not to have been taught of God: his own reason might teach him the conveniency of trumpets; but the constitution of Israel was to be in every thing divine, and therefore...

Commenting on Numbers 10:1-10

John Gill Reformed Baptist @doctorgill

And when they shall blow with them,.... With both the trumpets, in an even and continued sound, that is, the sons of Aaron: all the assembly shall assemble themselves to thee at the door of the tabernacle of the congregation; to hear what was to be said unto them: blowing both the trumpets together was a token that the whole congregation was called to meet...

Jamieson-Fausset-Brown Reformed @jfbcommentary

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...