Very early in the Sermon on the Mount, straight after the opening discourse on the blessings on mourners, peacemakers, and the merciful, Christ used two metaphors to describe what the disciples were to be: they were to be the salt of the earth, and the light of the world. We’re going to look at the first of these.
You are the salt of the earth; but if salt has lost its taste, how can its saltiness be restored? It is no longer good for anything, but is thrown out and trampled under foot. – Mt 5:131
The metaphor may not make much sense when we first encounter it. In what way are we salt? Is Christ speaking of table salt or sea salt? Maybe Himalayan rock salt? Mineral salts? Smelling salts? Is it good to be salt or bad? Also, how can the taste of salt be restored to salt that’s become tasteless? Does salt that’s lost its taste really have no use? Can salt even lose its taste? It all seems quite distant and hard to understand.
So, if we don’t understand it on our first go, let’s unpack it a little so we can at least understand the metaphor before we get into what we’re to learn from it.
Before we can establish what the salt is that we read about we need to understand what it means that it is the salt of the earth. Though it could be understood that this phrase is describing salt that is found in the ground, this is unlikely to be the correct interpretation. After all, ground spread with salt becomes infertile – when Abimelech captured Shechem, that’s exactly what he did to it – he sowed the ground with salt (Jdg 9:45). We find God threatening to do the same to Moab in Jeremiah 48:9. Rather, in the same way that the light was the light of the world, the salt was the salt of the earth – i.e. it was for the benefit of the world. In the same way that the light gives light to the whole house, whatever the beneficial property of salt was, the world benefits from the salt.2
Therefore, to better capture the sense of the phrase “You are the salt of the earth”, we could translate it “you are the salt for all humanity.”3 The word we’ve just translated humanity instead of “earth” is used with the same sense in Matthew 10:34:
Do not think that I have come to bring peace to the earth [i.e. humanity]; I have not come to bring peace, but a sword. – Mt 10:34
So, by seeing that the “light” idea that the “salt” is grouped with, and by also looking at the biblical evidence we can establish that the phrase isn’t talking about salt in the ground; rather it’s talking about the way that salt benefits the world.
Now that we’ve established that, what is meant by salt? The salt that we have on our tables didn’t exist back then. What do we know about salt in the time of the Bible? How would the Galileans listening to Christ have understood the term? Let’s step into their world for a moment.
When we look through the Old Testament we find that salt was used widely in the law. E.g. sacrifices were accompanied by salt:
You shall not omit from your grain offerings the salt of the covenant with your God; with all your offerings you shall offer salt. – Le 2:13
Not only was salt offered with sacrifices, it was also an ingredient of the incense that was offered on the altar of incense along with “sweet spices, stacte, onycha, galbanum, and frankincense” (Ex 30:34). It’s thought that salt was added to the incense for two reasons: to help preserve the mixture in storage, and to help it burn quicker when it was being offered on the altar of incense.4 Salt, it seems, played a big part in the law.
The Mishnah goes into some detail on how the various sacrifices were made, and we find the salt mentioned in the description of the offering of birds5: The priest would walk up the altar ramp, and walk over to the altar’s south-eastern corner. He’d wring off the bird’s head, separating it from its body, and drain the blood off onto the wall of the altar. He’d take the bird’s head, dry it with salt, and then toss it onto the fire. After plucking and gutting the body, it would also be dried with salt and then tossed on the fire (M. Zebachim 6:5). We may think it unpleasant, but this was how the law was kept – this was reality for the people that Christ lived among.
When we look wider than the service in the tabernacle and temples we find salt used when God described certain covenants, using the term “covenant of salt.” Here, the aspect of salt that’s important is that it preserves. A covenant of salt was one that would last forever, because it was based on a preservative:
All the holy offerings that the Israelites present to the LORD I have given to you, together with your sons and daughters, as a perpetual due; it is a covenant of salt forever before the LORD for you and your descendants as well. – Nu 18:19
We find the same idea in king Abijah’s speech to Jeroboam – he was making the point that Jeroboam’s kingship had no legitimacy:
Do you not know that the LORD God of Israel gave the kingship over Israel forever to David and his sons by a covenant of salt? – 2 Ch 13:5
We find the preservative idea in various Jewish commentaries on the law. Philo, a Jewish philosopher contemporary with Christ, wrote the following 6 about the passage in Leviticus we looked at earlier (Lev 2:13):
…he figuratively implies a duration for ever; for salt is calculated to preserve bodies… (The Special Laws, I 289)
Continuing with the idea of salt being used for preserving, bear in mind that it’s likely that many of the Galileans listening to Christ giving his Sermon on the Mount were fishermen, and the fishermen of the Sea of Galilee were experts at preserving their catch with salt. The fish of the Sea of Galilee were part of the staple diet in that area, so if you weren’t preserving fish, you were eating preserved fish.
Finally, salt was used back then in the same way that we most commonly use it today; as flavoring to improve the taste of whatever food we’re eating. It’s used that way in Colossians:
Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer everyone. – Col 4:6
Those are the aspects of salt that the ancients were interested in. That’s what the Galileans listening to Jesus would have thought of when he mentioned salt: it was a preservative, a symbol of eternity, a flavoring, and a necessity for life. This background information helps to enhance our understanding of Christ’s message in the verse we’re looking at. By entering the world of Christ’s audience we can more closely understand what they would have understood from this teaching.
When we continue reading the verse, we find which of those aspects Christ is focusing on. He asked a question: how can salt that’s lost its taste get a salty taste again? Christ appeared to be particularly interested in the flavor aspect of salt. It seems that if the salt has lost its taste, it was no good for anything. However, salt doesn’t lose its taste, so what does Christ mean?
The salt back then wasn’t like our salt at all. Their salt came from a number of places: the Dead Sea (Ezk 47:11), a large mountain of salt at the south-west corner of the Dead Sea today called “Mount Sodom” or Jebel Usdum7 (pictured above), and evaporation pans along the Mediterranean coastline.8 What they got from these sources was a very impure form of salt – the actual salt (i.e. the sodium chloride) was mixed in with dusty soil, lime, and all sorts of other bits. It wasn’t pure like our table salt at all.
Since only about one-third of the salt from the Dead Sea consists of kitchen salt and even in commerce was not sold without admixtures, the moisture can affect the more easily dissolved parts of the salt mixture and detract from its taste.9
So though it may seem like an impossibility to us, it was quite possible for what passed as salt back then to lose its saltiness – the sodium chloride very easily leeched out of what they had, leaving a pile of bland-tasting, dirty chalk. That is how salt could lose its taste. And if the sodium chloride was gone then the remaining dross served no purpose, so it was thrown out. It wasn’t thrown out in order for it to be trampled on, it was just thrown out. The result was that it was trampled on; it was not the intention of the throwing out. But it was thrown out.
So now let’s summarize the background: the salt is meant for the benefit of humanity, Jews in the 1st century considered salt to be an essential for life, they used it as a preservative and so it came to represent eternity, it was used for flavoring but due to the nature of salt back then the salt could lose its flavor. If it lost its flavor it wasn’t any use so it was thrown out.
Those who listen to Christ are supposed to somehow improve the flavor of the world. If they’re not doing that then they’re no good to anybody.
What Christ was teaching starts to become apparent: those who listen to Christ are supposed to somehow improve the flavor of the world. If they’re not doing that then they’re no good to anybody. We, as those who aim to listen to Christ, are supposed to improve the world’s flavor. It’s supposed to be improved by our presence. It’s very plain that that’s what it means, and it’s in the Sermon on the Mount so the teaching is vitally important. Christ was very serious about this point – we’re supposed to improve the state of things or we’re no good to anybody. Christ wanted humanity to benefit from the presence of his disciples. Notice that Christ’s focus is not on the preservative aspect – it’s not about preventing or holding back any moral slide in the world (though a number of commentators say that aspect is there in the text); the main focus is on improving the world. Humanity should “taste” better as a result of our being part of it.
The principle is clear: somehow, we are supposed to make the world a better place today. Not just wait around until the return of Christ. It’s not talking about attendance. It’s not talking about showing kindness just to those of us at our local church. We are supposed to be the salt of the earth.
We would do well to think about about what this means for each of us. Am I improving the state of humanity? Does the world benefit by my presence? Are people’s lives better as a result of what I am doing?
We could react by suggesting Maybe it’s just this one verse? If it’s just in one place then there must be other more important things to focus on instead of this? However, the questioned asked by the lawyer of Luke 10 may spring to mind:
Just then a lawyer stood up to test Jesus. “Teacher,” he said, “what must I do to inherit eternal life?” He said to him, “What is written in the law? What do you read there?” He answered, “You shall love the Lord your God with all your heart, and with all your soul, and with all your strength, and with all your mind; and your neighbor as yourself.” And he said to him, “You have given the right answer; do this, and you will live.” But wanting to justify himself, he asked Jesus, “And who is my neighbor?” – Lk 10:25–29
The lawyer modelled a common way to react to a passage with a similar idea to the one we’re looking at – the injunction to love your neighbor as yourself – he immediately tried to qualify it. Who is my neighbor? Jesus answered the question by way of a parable we’re probably familiar with: the Good Samaritan. What answer did the lawyer get? After Christ made the hero of the story a Samaritan, he explained that the Samaritan showed mercy and said to the lawyer: “Go and do likewise.” It’s not the righteous priest or the temple-serving Levite that we’re supposed to be like – it’s the Samaritan. He didn’t keep the Law, he wasn’t one of God’s people, he was a foreigner. But it’s him that we’re supposed to emulate. Why? Because he showed mercy to some random person he didn’t even know. He made the world taste a little better. Humanity was slightly improved by his actions. He stumbled across a situation he could help in, and he did.
Let’s take a look at Jesus and see how he improved the taste of the world. In Luke 7 we see Christ demonstrating this sort of improving the state of humanity thing. As he walked into the town of Nain he saw a funeral procession coming out. In the crowd was the grieving mother whose only son was about to be buried. What do we read? “When the Lord saw her, he had compassion for her…” He then proceeded to raise her son from the dead. Matt 14:14 “When he went ashore, he saw a great crowd; and he had compassion for them and cured their sick.” It seems when he saw human suffering his immediate response was to show compassion. To try to help. To show kindness. To improve the flavor of their lives. To benefit humanity.
Mk 8:1–3 In those days when there was again a great crowd without anything to eat, he called his disciples and said to them, “I have compassion for the crowd, because they have been with me now for three days and have nothing to eat. If I send them away hungry to their homes, they will faint on the way—and some of them have come from a great distance.”
In this passage there’s nothing but plain concern for the wellbeing of those around him. They were hungry, so he wanted to make sure they were fed.
It seems that as well as focusing on preaching and teaching, Christ was also very keen to improve the current state of people’s lives. He healed, he raised from the dead, he showed concern for the hungry, for the poor, the diseased. Very often the events were broadcast around the place and were ways for people to hear about Christ and his message, but that doesn’t seem to have been the reason Christ showed compassion and helped people. He spent a great deal of energy on being the salt of the earth – the flavor with which the world was improved. He really is a great example for us to follow for doing our bit to improve the world around us.
This passage shows that what we’re really looking at is not just the actions of Christ, but of the character of God:
Dt 10:16–19 Circumcise, then, the foreskin of your heart, and do not be stubborn any longer. For the LORD your God is God of gods and Lord of lords, the great God, mighty and awesome, who is not partial and takes no bribe, who executes justice for the orphan and the widow, and who loves the strangers, providing them food and clothing. You shall also love the stranger, for you were strangers in the land of Egypt.
This theme runs through scripture, from beginning to end, because God is a merciful god.
We can find the teaching about the salt of the earth challenging. It’s an aspect of the Christian life we may not have given much thought to in the past. What’s particularly challenging is how broad it is – improving the flavor of the world. It’s about actively looking after the fatherless and the widow, it’s about looking after the poor, and the stranger – it’s about flavoring humanity. We don’t need to fly to the 3rd world to do this; Christ just made the lives of those around him better. Let us, as his disciples, do the same.
- All scripture quotes from the New Revised Standard Version (Nashville: Thomas Nelson Publishers, 1989).
- “…the metaphor of the salt is interpreted by the genitive attribute ‘of the earth.’” Hans Dieter Betz, The Sermon on the Mount: A Commentary on the Sermon on the Mount, Including the Sermon on the Plain (Matthew 5:3-7:27 and Luke 6:20-49) (ed. Adela Yarbro Collins; Hermeneia—a Critical and Historical Commentary on the Bible; Minneapolis, MN: Fortress Press, 1995), 158.
- Johannes P. Louw and Eugene Albert Nida, Greek-English Lexicon of the New Testament: Based on Semantic Domains (New York: United Bible Societies, 1996), 105. See also William Arndt, Frederick W. Danker, and Walter Bauer, A Greek-English Lexicon of the New Testament and Other Early Christian Literature (Chicago: University of Chicago Press, 2000), 196.
- R. Alan Cole, Exodus: An Introduction and Commentary (vol. 2; Tyndale Old Testament Commentaries; Downers Grove, IL: InterVarsity Press, 1973), 216–217.
- Jacob Neusner, The Mishnah : A New Translation (New Haven, CT: Yale University Press, 1988), 710.
- Charles Duke Yonge with Philo of Alexandria, The Works of Philo: Complete and Unabridged (Peabody, MA: Hendrickson, 1995), 561.
- Tourists know this as the location of “Lot’s Wife”
- R. K. Harrison, “Salt,” ed. D. R. W. Wood et al., New Bible Dictionary (Leicester, England; Downers Grove, IL: InterVarsity Press, 1996), 1046. See also Avraham Negev, “Salt”, The Archaeological Encyclopedia of the Holy Land (New York: Prentice Hall Press, 1990).
- Ulrich Luz, Matthew 1–7: A Commentary on Matthew 1–7 (ed. Helmut Koester; Rev. ed.; Hermeneia—a Critical and Historical Commentary on the Bible; Minneapolis, MN: Fortress Press, 2007), 206.