1 Corinthians 14:8-10

World English Bible

⁸ For if the trumpet gave an uncertain sound, who would prepare himself for war? ⁹ So also you, unless you uttered by the tongue words easy to understand, how would it be known what is spoken? For you would be speaking into the air. ¹⁰ There are, it may be, so many kinds of languages in the world, and none of them is without meaning.