Exodus 19:16 (KJV)
And it came to pass on the third dayin the morningthat there were thundersand lightningsand a thick cloudupon the mountand the voiceof the trumpet exceeding loudso that all the peoplethat was in the camp trembled
And it came to pass on the third dayin the morningthat there were thundersand lightningsand a thick cloudupon the mountand the voiceof the trumpet exceeding loudso that all the peoplethat was in the camp trembled