1 Corinthians 14:8-10

Complete Jewish Bible

⁸ And if the bugle gives an unclear sound, who will get ready for battle? ⁹ It’s the same with you: how will anyone know what you are saying unless you use your tongue to produce intelligible speech? You will be talking to the air! ¹⁰ There are undoubtedly all kinds of sounds in the world, and none is altogether meaningless;