New Defender's Study Bible Notes
19:19 voice of the trumpet. There seems to have been a host of angels present around Mount Sinai as the Law was being given (note Acts 7:53; Galatians 3:19) and one or more were blowing loudly on the trumpet of God. This, along with the lightning and dark cloud and great quaking of the mountain, made an awe-inspiring spectacle which the people could never forget (or so it would have seemed). Compare the exposition of this scene in Hebrews 12:18-21.