Parallel
1 Corinthians 14:11
Robinson-Pierpont Byzantine Textform · Berean Standard Bible
Ἐὰν οὖν μὴ εἰδῶ τὴν δύναμιν τῆς φωνῆς, ἔσομαι τῷ λαλοῦντι βάρβαρος, καὶ ὁ λαλῶν ἐν ἐμοὶ βάρβαρος.
If, then, I do not know the meaning of someone’s language, I am a foreigner (note: Literally a barbarian; twice in this verse) to the speaker, and he is a foreigner to me.