Moses
Numbers 10:7ESV·traditional attribution

But when the assembly is to be gathered together, you shall blow a long blast, but you shall not sound an alarm.

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

But when the congregation is to be gathered together,.... At the door of the tabernacle of the congregation, and not to move in separate camps or bodies one after another: you shall blow, but you shall not sound an alarm; blow with an even and uninterrupted sound, and not with a broken and quavering one; by which the congregation and camps were distinguished from one...

Keil & Delitzsch Lutheran @keilanddelitzsch

Num 10:7 But to call the congregation together they were to blow, not to sound an alarm. תּקע signifies blowing in short, sharp tones. הריע = תּרוּעה תּקע, blowing in a continued peal.