John Calvin Commentary 1 Corinthians 14:11

"If then I know not the meaning of the voice, I shall be to him that speaketh a barbarian, and he that speaketh will be a barbarian unto me." — 1 Corinthians 14:11 (ASV)

I shall be to him that speaketh a barbarian. The tongue should be an index of the mind—not merely in the sense of the proverb, but in the sense that Aristotle explains in the beginning of his book, “On Interpretation.” How foolish and preposterous it is, then, for a person to utter in an assembly a voice that the hearer does not understand, and in which the hearer perceives no sign from which to learn what the speaker means!

It is not without good reason, therefore, that Paul views it as the height of absurdity for a person to be a barbarian to the hearers by chattering in an unknown tongue, while at the same time he elegantly derides the foolish ambition of the Corinthians, who were eager to obtain praise and fame by this means.

“This reward,” he says, “you will earn—that you will be a barbarian.” For the term barbarian, whether it is an artificial one (as Strabo thinks) or derived from some other origin, is taken in a bad sense. Hence the Greeks, who considered themselves the only people who were good speakers and had a polished language, called all others barbarians because of their rude and rustic dialect.

No language, however, is so cultivated as not to be considered barbarous when it is not understood. “He that heareth,” says Paul, “will be unto me a barbarian, and I will be so to him in return.” By these words he implies that to speak in an unknown tongue is not to have fellowship with the Church, but rather to keep separate from it; and that whoever acts this part will be deservedly despised by others, because he first despises them.