2 for he who is speaking in an 'unknown' tongue—to men he doth not speak, but to God, for no one doth hearken, and in spirit he doth speak secrets; 3 and he who is prophesying to men doth speak edification, and exhortation, and comfort; 4 he who is speaking in an 'unknown' tongue, himself doth edify, and he who is prophesying, an assembly doth edify; 5 and I wish you all to speak with tongues, and more that ye may prophecy, for greater is he who is prophesying than he who is speaking with tongues, except one may interpret, that the assembly may receive edification.

6 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 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 for if also an uncertain sound a trumpet may give, who shall prepare himself for battle? 9 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. 10 There are, it may be, so many kinds of voices in the world, and none of them is unmeaning, 11 if, then, I do not know the power of the voice, I shall be to him who is speaking a foreigner, and he who is speaking, is to me a foreigner; 12 so also ye, since ye are earnestly desirous of spiritual gifts, for the building up of the assembly seek that ye may abound;

Matthew Henry's Commentary on 1 Corinthians 14:2-12

Commentary on 1 Corinthians 14:1-5

(Read 1 Corinthians 14:1-5)

Prophesying, that is, explaining Scripture, is compared with speaking with tongues. This drew attention, more than the plain interpretation of Scripture; it gratified pride more, but promoted the purposes of Christian charity less; it would not equally do good to the souls of men. What cannot be understood, never can edify. No advantage can be reaped from the most excellent discourses, if delivered in language such as the hearers cannot speak or understand. Every ability or possession is valuable in proportion to its usefulness. Even fervent, spiritual affection must be governed by the exercise of the understanding, else men will disgrace the truths they profess to promote.

Commentary on 1 Corinthians 14:6-14

(Read 1 Corinthians 14:6-14)

Even an apostle could not edify, unless he spoke so as to be understood by his hearers. To speak words that have no meaning to those who hear them, is but speaking into the air. That cannot answer the end of speaking, which has no meaning; in this case, speaker and hearers are barbarians to each other. All religious services should be so performed in Christian assemblies, that all may join in, and profit by them. Language plain and easy to be understood, is the most proper for public worship, and other religious exercises. Every true follower of Christ will rather desire to do good to others, than to get a name for learning or fine speaking.