In the {r} law it is written, With men of other tongues and other lips will I speak unto this people; and yet for all that will they not hear me, saith the Lord.

(r) By the law he understands the entire scripture.

People's New Testament

14:21 In the law it is written. For the quotation, see Isa 28:11,12. The Jews were there told that for their sins they would be carried into the Assyrian captivity, where they would hear strange languages. This was a judgment. Wherefore, do not force the church to listen to listen to strange tongues which serve to remind of the judgment of Israel.

Wesley's Notes

14:21 It is written in the Law - The word here, as frequently, means the Old Testament. In foreign tongues will I speak to this people - And so he did. He spake terribly to them by the Babylonians, when they had set at nought what he had spoken by the prophets, who used their own language. These words received a farther accomplishment on the day of pentecost. Isaiah 28:11.

Jamieson-Fausset-Brown Bible Commentary

21. In the law-as the whole Old Testament is called, being all of it the law of God. Compare the citation of the Psalms as the "law," Joh 10:34. Here the quotation is from Isa 28:11, 12, where God virtually says of Israel, This people hear Me not, though I speak to. them in the language with which they are familiar; I will therefore speak to them in other tongues, namely, those of the foes whom I will send against them; but even then they will not hearken to Me; which Paul thus applies, Ye see that it is a penalty to be associated with men of a strange tongue, yet ye impose this on the Church [Grotius]; they who speak in foreign tongues are like "children" just "weaned from the milk" (Isa 28:9), "with stammering lips" speaking unintelligibly to the hearers, appearing ridiculous (Isa 28:14), or as babbling drunkards (Ac 2:13), or madmen (1Co 14:23).

Matthew Henry's Concise Commentary

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.

Matthew Henry's Whole Bible Commentary

Verses 21-25

In this passage the apostle pursues the argument, and reasons from other topics; as,

I. Tongues, as the Corinthians used them, were rather a token of judgment from God than mercy to any people (v. 21): In the law (that is, the Old Testament) it is written, With men of other tongues and other lips will I speak to this people; and yet for all this they will not hear me, saith the Lord, Isa. 28:11. Compare Deu. 28:46, 49. To both these passages, it is thought, the apostle refers. Both are delivered by way of threatening, and one is supposed to interpret the other. The meaning in this view is that it is an evidence that a people ar abandoned of God when he gives them up to this sort of instruction, to the discipline of those who speak in another language. And surely the apostle's discourse implies, "You should not be fond of the tokens of divine displeasure. God can have no gracious regards to those who are left merely to this sort of instruction, and taught in language which they cannot understand. They can never be benefited by such teaching as this; and, when they are left to it, it is a sad sign that God gives them over as past cure." And should Christians covet to be in such a state, or to bring the churches into it? Yet thus did the Corinthian preachers in effect, who would always deliver their inspirations in an unknown tongue.

II. Tongues were rather a sign to unbelievers than to believers, v. 22. They were a spiritual gift, intended for the conviction and conversion of infidels, that they might be brought into the Christian church; but converts were to be built up in Christianity by profitable instructions in their own language. The gift of tongues was necessary to spread Christianity, and gather churches; it was proper and intended to convince unbelievers of that doctrine which Christians had already embraced; but prophesying, and interpreting scripture in their own language, were most for the edification of such as did already believe: so that speaking with tongues in Christians assemblies was altogether out of time and place; neither one nor the other was proper for it. Note, That gifts may be rightly used, it is proper to know the ends which they are intended to serve. To go about the conversion of infidels, as the apostles did, had been a vain undertaking without the gift of tongues, and the discovery of this gift; but, in an assembly of Christians already converted to the Christian faith, to make use and ostentation of this gift would be perfectly impertinent, because it would be of no advantage to the assembly; not for conviction of truth, because they had already embraced it; not for their edification, because they did not understand, and could not get benefit without understanding, what they heard.

III. The credit and reputation of their assemblies among unbelievers required them to prefer prophesying before speaking with tongues. For, 1. If, when they were all assembled for Christian worship, their ministers, or all employed in public worship, should talk unintelligible language, and infidels should drop in, they would conclude them to be mad, to be no better than a parcel of wild fanatics. Who in their right senses could carry on religious worship in such a manner? Or what sort of religion is that which leaves out sense and understanding? Would not this make Christianity ridiculous to a heathen, to hear the ministers of it pray, or preach, or perform any other religious exercise, in a language that neither he nor the assembly understood? Note, The Christian religion is a sober and reasonable thing in itself, and should not, by the ministers of it, be made to look wild or senseless. Those disgrace their religion, and vilify their own character, who do any thing that has this aspect. But, on the other hand, 2. If, instead of speaking with tongues, those who minister plainly interpret scripture, or preach, in language intelligible and proper, the great truths and rules of the gospel, a heathen or unlearned person, coming in, will probably be convinced, and become a convert to Christianity (v. 24, 25); his conscience will be touched, the secrets of his heart will be revealed to him, he will be condemned by the truth he hears, and so will be brought to confess his guilt, to pay his homage to God, and own that he is indeed among you, present in the assembly. Note, Scripture-truth, plainly and duly taught, has a marvellous aptness to awaken the conscience, and touch the heart. And is not this much more for the honour of our religion than that infidels should conclude the ministers of it a set of madmen, and their religious exercises only fits of frenzy? This last would at once cast contempt on them and their religion too. Instead of procuring applause for them, it would render them ridiculous, and involve their profession in the same censure: whereas prophesying would certainly edify the church, much better keep up their credit, and might probably convince and convert infidels who might occasionally hear them. Note, Religious exercises in Christian assemblies should be such as are fit to edify the faithful, and convince, affect, and convert unbelievers. The ministry was not instituted to make ostentation of gifts and parts, but to save souls.