Both words only here in Paul. The metaphor is from the office of salt in rendering palatable. Both in Greek and Latin authors, salt was used to express the pungency and wittiness of speech. Horace speaks of having praised a poet for rubbing the city with abundant salt, i.e., for having wittily satirized certain parties so as to make them smart as if rubbed with salt, and so as to excite the laughter of those who are not hit (“Satires,” 1 x., 3). Lightfoot gives some interesting citations from Plutarch, in which, as here, grace and salt are combined. Thus: “The many call salt χάριτας graces, because, mingled with most things, it makes them agreeable and pleasant to the taste.” Seasoned is, literally, prepared. It is not likely that the fact has any connection with this expression, but it is interesting to recall Herodotus' story of a salt lake in the neighborhood of Colossae, which has been identified, and which still supplies the whole surrounding country with salt (vii., 30). The exhortation to well-seasoned and becoming speech is expanded in Eph 4:29; Eph 5:4, in a warning against corrupt communication.