1 Corinthians 14
6 Ref And now, brethren, if I may come unto you speaking tongues, what shall I profit you, except I shall speak to you either in revelation, or in knowledge, or in prophesying, or in teaching?
7 Ref yet the things without life giving sound -- whether pipe or harp -- if a difference in the sounds they may not give, how shall be known that which is piped or that which is harped?
8 Ref for if also an uncertain sound a trumpet may give, who shall prepare himself for battle?
9 Ref 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.