Again, if the trumpet sounds a muffled call, who will prepare for battle?
In this paragraph he goes on to show how vain a thing the ostentation of speaking unknown and unintelligible language must be. It was altogether unedifying and unprofitable (Co1 14:6): If I come to you speaking with tongues, what will it profit you, unless I speak to you by revelation, or by knowledge, or by prophesying, or by doctrine?
Commenting on 1 Corinthians 14:6-14
For if the trumpet give an uncertain sound,.... That is not plain and manifest, so as that it cannot be known on what account it is given: who shall prepare himself to the battle? the allusion is to the custom of many nations, Jews and others, who, when about to engage in war, made use of musical instruments, particularly the trumpet, to gather the soldiers...
Verse 8. For if the trumpet give an uncertain sound. The trumpet was used commonly in war. It is a well-known wind instrument, and was made of brass, silver, etc. It was used for various purposes in war--to summon the soldiers; to animate them in their march; to call them forth to battle; to sound a retreat; and to signify to them what they were...