Moses
Exodus 19:19ESV·traditional attribution

And as the sound of the trumpet grew louder and louder, Moses spoke, and God answered him in thunder.

Matthew Henry Presbyterian @wholebiblehenry

Now, at length, comes that memorable day, that terrible day of the Lord, that day of judgment, in which Israel heard the voice of the Lord God speaking to them out of the midst of the fire, and lived, Deu 4:33. Never was there such a sermon preached, before nor since, as this which was here preached to the church in the wilderness. For, I.

Commenting on Exodus 19:16-25

John Gill Reformed Baptist @doctorgill

And when the voice of the trumpet sounded long,.... Not in one continued tone, as before, Exo 19:13, where a different word is used, and when it decreased, and was about to cease, which was to summon the people to attend; but now they were come to the foot of the mount, and this sounding was a preparation to the giving of the law unto...

Geneva Bible Notes Reformed @genevanotes

And when the voice of the trumpet sounded long, and waxed louder and louder, Moses spake, and God answered him by a voice. (h) He gave authority to Moses by plain words, that the people might understand him.