Clement of Alexandria, on 1Cor 14:9

“So likewise you, except you utter by the tongue plain speech, how shall it be known what is said? For you shall be speaking into the air.”

“You see that the barbarian philosophy professes deeds, not words. The apostle thus speaks: "So likewise ye, except ye utter by the tongue a word easy to be understood, how shall ye know what is spoken? for ye shall speak into the air. There are, it may be, so many kind of voices in the world, and none of them is without signification. Therefore if I know not the meaning of the voice, I shall be unto him that speaketh a barbarian, and he that speaketh shall be a barbarian unto me." And, "Let him that speaketh in an unknown tongue pray that he may interpret."”

Imported from an open dataset — not yet checked against the printed edition.