The Apostle Paul
1 Corinthians 14:11ESV·traditional attribution

but if I do not know the meaning of the language, I will be a foreigner to the speaker and the speaker a foreigner to me.

John Calvin Reformed @genevareformer

11. I shall be to him that speaketh a barbarian “The Greeks, after the custom of the Egyptians, mentioned by; Herodotus, (lib. 2,) called all those barbarians who did not speak their language. In process of time, however, the Romans having subdued the Greeks, delivered themselves by the force of arms from that opprobrious appellation; and joined the Greeks in calling all barbarians who did...

Matthew Henry Presbyterian @wholebiblehenry

In this paragraph he goes on to show how vain a thing the ostentation of speaking unknown and unintelligible language must be. It was altogether unedifying and unprofitable (Co1 14:6): If I come to you speaking with tongues, what will it profit you, unless I speak to you by revelation, or by knowledge, or by prophesying, or by doctrine?

Commenting on 1 Corinthians 14:6-14

John Gill Reformed Baptist @doctorgill

Therefore if I know not the meaning of the voice,.... The force and power of a language, the signification of it, the ideas its words convey, but only hear the sound of it: I shall be to him that speaketh a barbarian, and he that speaketh shall be a barbarian unto me: like one of those rude and uncultivated people that inhabit deserts and wild...