1 Corinthians 14:2

2The [one]ὁforγὰρspeakingλαλῶνin a tongueγλώσσῃnotοὐκto menἀνθρώποιςspeaksλαλεῖbutἀλλὰto Godθεῷ,no oneοὐδεὶςforγὰρhearsἀκούει,in the Spiritπνεύματιhoweverδὲhe uttersλαλεῖmysteriesμυστήρια·

For the one speaking in a tongue speaks not to men, but to God. For no one hears, but in the Spirit he speaks mysteries.