1 Corinthians 14:7-9

Darby Translation

⁷ Even lifeless things giving a sound, whether pipe or harp, if they give not distinction to the sounds, how shall it be known what is piped or harped?

⁸ For also, if the trumpet give an uncertain sound, who shall prepare himself for war?

⁹ Thus also *ye* with the tongue, unless ye give a distinct speech, how shall it be known what is spoken? for ye will be speaking to the air.