Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer every one. (Col 4:6 RSV)
It is kind of a weird idea. I mean, how do you put salt on your speech? And if you could, what would that even mean? I know Jesus tells us “you are the salt of the earth” (Matt 5:13). He seems to mean that believers, disciples, make the world tasty to God. That is, the followers of Jesus enhance the world, make it better, spread the tastiness of the gospel and shed light through their preaching. Even then, he warns that salt can lose its flavor and be good for nothing (Mark 9:50||Luke 14:34). In both cases, Jesus and Paul, salt indicates the relation of the believer with the world–enhancing one’s conversation with the world or enhancing the world as a whole.
Yet the connection I found was more textual. Only one other place in the Bible does the phrase “seasoned with salt” appear. Here:
and make an incense blended as by the perfumer, seasoned with salt, pure and holy; (Exo 30:35 RSV)
It’s part of one of the few recipes in the Bible. This recipe is for the incense which will be used in the tabernacle and temple sanctuary. If Paul is alluding back to this Exodus recipe, what could he mean? Is he highlighting the sacred nature of Christian speech, that conversation with unbelievers takes on an almost prayerful/worshipful aspect, so much so as being similar to the holy incense offered in the temple?
Some offerings are also seasoned with salt (Lev 2:13) and the Lord even makes a “covenant of salt” (Num 18:19), but I think the main thrust in Paul here links up nicely with Exodus 30:35. Strangely, the Hebrew alone preserves the idea that Paul references. The Hebrew has memulach, which is a pual participle meaning “seasoned with salt.” This is rendered in LXX as memigmenon, which simply means “mixed.” Paul’s phrasing in Colossians 4:6 is halati ertumenos, which clearly relies on the Hebrew, not the Greek. The participle here is from artuo, which means “to make salty” and halati means “with salt.” So we could translate Paul’s phrase as “to make salty with salt.” (One could easily think up some late nineties references here.)
I think the point of Paul’s encouragement is relatively simple: that our spoken words be kind and Christlike, “in grace” and not in malice. The connection with incense highlights the holiness, purity and God-directedness of our speech, but the connection with Jesus’ salt sayings, like “have salt in yourselves” (Luke 14:34), emphasizes the good effects our salty words can have in the world around us.