1 Corinthians 14:9-11

Mace(i) 9 in like manner, if you express yourselves in words of obscure signification, you may as well talk to the wind, for how shall any comprehend you? 10 there are, it may be, as many different languages in the world as there are people, and none of them without signification. 11 therefore if I don't know the meaning of the language, with respect to him that speaks, I shall be a barbarian; and he that speaks shall be a barbarian to me.