1 Corinthians 14:8-10

Young's Literal Translation

⁸ for if also an uncertain sound a trumpet may give, who shall prepare himself for battle?

⁹ so also ye, if through the tongue, speech easily understood ye may not give -- how shall that which is spoken be known? for ye shall be speaking to air.

¹⁰ There are, it may be, so many kinds of voices in the world, and none of them is unmeaning,