1 Corinthians 14:6-9

Goodspeed(i) 6 But as it is brothers, if I come back to you and speak ecstatically, what good will I do you, unless I have some revelation or special knowledge or message or teaching to give you? 7 Even inanimate things, like the flute or the harp, may produce sound, but if there is no difference in the notes, how can you tell what is being played? 8 If the bugle does not sound a clear call, who will prepare for battle? 9 So if you in your ecstatic speaking utter words no one can understand, how will people know what you are saying? You will be talking to the empty air!