1 Corinthians 14:27,28 - Joseph Benson’s Commentary on the Old and New Testaments

If any man speak That is, be moved to speak; in an unknown tongue, let it be by two, or, at the most, three Let not above two or three speak at one meeting; and that by course That is, one after another; and let one interpret What is said, into the vulgar tongue. It seems, the gift of tongues was an instantaneous knowledge of a tongue, till then unknown, which he that received it could afterward speak when he thought fit, without any new miracle. But if there be no interpreter present, let him The person speaking in a foreign language; be silent in the church Where he can do no manner of service by uttering what none but himself can understand; and let him speak in that tongue to himself and to God Make use of his gift in his own private devotions, if he find it profitable so to do. From its being here ordered that, if no interpreter were present, the person who spoke in a foreign language must be silent, Macknight infers that, even if the inspired person were able to interpret the foreign language in which a revelation was given to him, he was not permitted to do it; “because, to have delivered the revelation first in the foreign language, and then in a known tongue, would have been an ostentation of inspiration, of which the church would not approve; not to mention that it would have wasted much time to no purpose. Whereas, when one spake a revelation in a foreign language, and another interpreted what he spake, the church was edified, not only by the things spoken, thus made known to them, but also by having an undoubted proof of the inspiration of the person who spake, given them in the inspired interpretation of what he spake.'