1 Corinthians 14:7-9

New American Standard Bible

⁷ Yet even lifeless instruments, whether flute or harp, in producing a sound, if they do not produce a distinction in the tones, how will it be known what is played on the flute or on the harp? ⁸ For if ^(A)the trumpet produces an indistinct sound, who will prepare himself for battle? ⁹ So you too, unless you produce intelligible speech by the tongue, how will it be known what is spoken? For you will just be ^(B)talking to the air.