1 Corinthians 14:9

New Revised Standard Version Catholic Interconfessional

So with yourselves; if in a tongue you utter speech that is not intelligible, how will anyone know what is being said? For you will be speaking into the air.

Cross References

1 Corinthians 14:10

There are doubtless many different kinds of sounds in the world, and nothing is without sound.

1 Corinthians 9:26

So I do not run aimlessly, nor do I box as though beating the air;