John Calvin on 1 Corinthians 14:27

27. If any one speak in another tongue He now describes the order and limits the measure. “If you have a mind to speak with other tongues, let only two speak, or, at most, not more than three, and let there be at the same time an interpreter sitting by Without an interpreter, tongues are of no advantage: let them, therefore be dispensed with.” It is to be observed, however, that he does not command, but merely permits; for the Church can, without any inconvenience, dispense with tongues, except in so far as they are helps to prophecy, as the Hebrew and Greek languages are at this day. Paul, however, makes this concession, that he may not seem to deprive the assembly of believers of any gift of the Spirit.

At the same time, it might seem as if even this were not agreeable to reason, inasmuch as he said before, (1 Corinthians 14:22,) that tongues, in so far as they are for a sign, are suited to unbelievers. I answer, that, while a miracle may be performed more particularly with a view to unbelievers, it, nevertheless, does not follow, that it may not be of some advantage to believers also. If you understand, that an unknown tongue is a sign to unbelievers in the sense that Isaiah’s words The words referred to are those which Paul had quoted above in 1 Corinthians 14:21. — Ed. bear, the method of procedure, which Paul here prescribes, is different. For he allows of other tongues in such a way that, interpretation being joined with them, nothing is left obscure. He observes, therefore, a most admirable medium in correcting the fault of the Corinthians. On the one hand, he does not at all set aside any gift of God whatever, “Tant petit soit-il;” — “Be it ever so small.” in order that all his benefits may be seen among believers. On the other hand he makes a limitation — that ambition do not usurp the place that is due to the glory of God, and that no gift of inferior importance stand in the way of those that are of chief moment; and he adds the sauce “Ascauoir l’interpretation;” — “Namely, the interpretation.” — that there be no mere ostentation, devoid of advantage.