Having said what should be the case, he adds what must above all be the case, which is this, that we should “give thanks”—to God, without doubt, but also to other people. Hence he uses the term thanksgiving without qualification. .
Nor obscenity. What is here meant by this word, St. Chrysostom tells us at large in the moral exhortation after his 17th homily; to wit, jests with immodest suggestions or a double meaning, and raillery or buffoonery against the rules of good conversation, scarce made use of by any but by men of low condition and of a mean genius, which is not to the purpose of a Christian, who must give an account to God of all his words. (Witham)
The “silly talk” to which Paul refers occurs not only among those who tell dirty jokes to get a cheap laugh. He is also referring to those who put on frivolous airs and to those who manipulate whoever they are trying to please. There is another kind of silly talk that occurs among those reckoned to be the intellectuals of the age who, when disputing on matters of natural science, imagine that they have fully comprehended the sands of the shore, the drops of ocean, the extent of heavens and the minuteness of earth…. Note that levity follows silly talk. The intent here is to speak of frivolous and inappropriate stories. The difference between silliness and levity is this: silliness has nothing in it that is wise or worthy of the human heart. Levity devolves from a clever mind and deliberately seeks out certain words, be they witty, vulgar, obscene or facetious, in a jocularity the sole aim of which is to get a laugh. –.
Have no witticisms, no obscenities, either in word or in deed, and you will quench the flame— let them not even be named, says he, among you, that is, let them not anywhere even make their appearance. This he says also in writing to the Corinthians. It is actually reported that there is fornication among you 1 Corinthians 5:1; as much as to say, Be all pure. For words are the way to acts. Then, that he may not appear a forbidding kind of person and austere, and a destroyer of playfulness, he goes on to add the reason, by saying, which are not befitting, which have nothing to do with us— but rather giving of thanks. What good is there in uttering a witticism? thou only raisest a laugh. Tell me, will the shoemaker ever busy himself about anything which does not belong to or befit his trade? Or will he purchase any tool of that kind? No, never. Because the things we do not need, are nothing to us.
Moral. Let there not be one idle word; for from idle words we fall also into foul words. ...
Let there be no obscenities, either in word or deed, that might quench the flame of the spirit. For words often lead the way to actions. Then, in order that it may not appear that he is a spoilsport or too austere, Paul gently shows that he is not an opponent of playfulness. For he qualifies this instruction by explaining its reason: You are not to indulge in that form of silly talk that is “not befitting” to this community. Better to offer thanksgiving than to spew out such talk. What good is it if you make an unbefitting witticism? All you have done is raise a laugh. Tell me, does the shoemaker use any instrument that does not befit his trade? Would he purchase a tool that does not contribute to his craft? Of course not. Similarly, that which is of no use to our purpose is nothing to us…. Inordinate levity may easily open the door to blasphemy, and the blasphemer heaps up countless other evils for himself. .