EJ2000(i)
6 ¶ Now, brothers, if I come unto you speaking with tongues, what shall I profit you unless I speak to you either with revelation or with knowledge or with prophecy or with doctrine?
7 And even things without life giving sound, whether flute or harp, except they give a distinction in the sounds, how shall it be known what is played or harped?
8 For if the trumpet gives an uncertain sound, who shall prepare himself to the battle?
9 So likewise ye, except ye utter by the tongue a clear and definite word, how shall it be known what is spoken? for ye shall speak into the air.