Passage
and a sound of a trumpet, and a voice of sayings, which those having heard did entreat that a word might not be added to them,
and a sound of a trumpet, and a voice of sayings, which those having heard did entreat that a word might not be added to them,
Hebrews 12:17 for ye know that also afterwards, wishing to inherit the blessing, he was disapproved of, for a place of reformation he found not, though with tears having sought it.
Hebrews 12:18 For ye came not near to the mount touched and scorched with fire, and to blackness, and darkness, and tempest,
Hebrews 12:19 and a sound of a trumpet, and a voice of sayings, which those having heard did entreat that a word might not be added to them,
Hebrews 12:20 for they were not bearing that which is commanded, `And if a beast may touch the mountain, it shall be stoned, or with an arrow shot through,'
Hebrews 12:21 and, (so terrible was the sight,) Moses said, `I am fearful exceedingly, and trembling.'
The verse centers on "sound", "trumpet", "voice", "sayings", "having", "heard", "entreat", and "word". It is saying that the verse draws attention to "sound" and "trumpet", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 18's "For ye came not near to the..." into verse 20's "for they were not bearing that which...", so "sound" and "trumpet" belong inside that flow. In Hebrews context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "sound" and "trumpet" with trust shaped by these words, not by a vague optimism outside the passage.