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; 13 wherefore he who is speaking in an 'unknown' tongue—let him pray that he may interpret; 14 for if I pray in an 'unknown' tongue, my spirit doth pray, and my understanding is unfruitful.
15 What then is it? I will pray with the spirit, and I will pray also with the understanding; I will sing psalms with the spirit, and I will sing psalms also with the understanding; 16 since, if thou mayest bless with the spirit, he who is filling the place of the unlearned, how shall he say the Amen at thy giving of thanks, since what thou dost say he hath not known? 17 for thou, indeed, dost give thanks well, but the other is not built up! 18 I give thanks to my God—more than you all with tongues speaking— 19 but in an assembly I wish to speak five words through my understanding, that others also I may instruct, rather than myriads of words in an 'unknown' tongue.
Matthew Henry's Commentary on 1 Corinthians 14:9-19
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.
Commentary on 1 Corinthians 14:15-25
(Read 1 Corinthians 14:15-25)
There can be no assent to prayers that are not understood. A truly Christian minister will seek much more to do spiritual good to men's souls, than to get the greatest applause to himself. This is proving himself the servant of Christ. Children are apt to be struck with novelty; but do not act like them. Christians should be like children, void of guile and malice; yet they should not be unskilful as to the word of righteousness, but only as to the arts of mischief. It is a proof that a people are forsaken of God, when he gives them up to the rule of those who teach them to worship in another language. They can never be benefitted by such teaching. Yet thus the preachers did who delivered their instructions in an unknown tongue. Would it not make Christianity ridiculous to a heathen, to hear the ministers pray or preach in a language which neither he nor the assembly understood? But if those who minister, plainly interpret Scripture, or preach the great truths and rules of the gospel, a heathen or unlearned person might become a convert to Christianity. His conscience might be touched, the secrets of his heart might be revealed to him, and so he might be brought to confess his guilt, and to own that God was present in the assembly. Scripture truth, plainly and duly taught, has a wonderful power to awaken the conscience and touch the heart.