1 Corinthians 14:9
So it is with you, unless you utter by the tongue speech that is intelligible, how will anyone know what is spoken? For you will be speaking into the air.
1 Corinthians 9:26
Therefore I do not run aimlessly. I do not box as a man beating the air.
Treasury of Scripture Knowledge
Summary
So likewise ye, except ye utter by the tongue words easy to be understood, how shall it be known what is spoken? for ye shall speak into the air.
Easy
Bible References
Easy
1 Corinthians 14:19
but in the church I would rather speak five words with my mind, to instruct others, than ten thousand words in a tongue.
For
1 Corinthians 9:26
Therefore I do not run aimlessly. I do not box as a man beating the air.