Matthew 5:13

“You are the salt of the earth,

But if the salt have lost its savour,

With what will it be salted?

It is from then on good for nothing,

But to be cast out and trodden under foot of men.”

‘You are the salt of the earth.' While these salts were sometimes used as fertiliser they were not very effective as such, and that idea is probably not intended here. The meaning rather is that the disciples are like salt among the people of the world, and the thought of its uniqueness is in mind. There is no replacement for salt. In the same way His disciples were to recognise that they too were unique in the world (as Christians also ought to be, but for the right reasons, not because of peculiarities of behaviour). Salt was famed for its preservative qualities, and for making things palatable. It prevented corruption advancing so quickly, and brought out what was good in food. And it thus both kept things edible and made them enjoyable. It could also be used as a cleansing agent (Exodus 30:35; 2 Kings 2:19; Ezekiel 16:4). In the same way the disciples, behaving in the way described in Matthew 5:3, will slow down the corruption in the world, and make the world itself a better place by the effects of their example and their teaching, slowing down the spread of corruption, making the world a more tasty place by transforming many of those who are within it, and having a continuing purifying effect.

Note the ‘YOU are' (the ‘you' is emphatic). This was spoken to His disciples, not the general run of people. It refers to the same ones as were to be persecuted and reviled for Jesus' sake (Matthew 5:11). The emphasis may be as a contrast to those who would revile them, or it may simply be a positive assessment of them in contrast to the rest of the world. We should note in passing that they are not told to ‘become salt'. That has already been done for them by God. They are rather to reveal the saltiness that God has put within them.

Salt was also used by the Rabbis as a symbol of wisdom (see Colossians 4:6). This may explain the use above of the Greek verb ‘become foolish' which probably translates the Aramaic ‘tapel'. This was closely associated with ‘tabel' which indicates to lose taste and may disguise a typical play on words of a type that Jesus loved. This then reveals the disciples as also being the source of the true wisdom in the world. They are being trained up by Jesus in order to be the world's source of true wisdom. How sad then if they cease to do His will and become foolish.

But what if through neglect the salt lose its savour? Then it will be useless. It will cease to have any effect and will become fit only to be thrown out onto the streets, to be treated with the contempt that it deserves. This is looking back to His previous indication that the disciples are replacing the prophets, and is introducing the warning of the danger of becoming false prophets, which will be developed in more detail towards the end (Matthew 7:15). It is therefore at this stage a warning to be careful how they behave, and how they learn and teach.

‘With what will it be salted?' There is no way of restoring saltiness to the mass of chemicals that the dissolving of the sodium chloride (salt) has left behind. In the same way once His disciples have lost their way they will find it very difficult to get back to what they were (but thank God not impossible, for at that point there is a difference. We are dealing with God's ability to restore. God can ‘make it again' (Jeremiah 18:4). But this must not be presumed upon). All they can then hope for is to be tossed out for the rubbish collector to collect, meanwhile being trodden over by heedless men and women.

‘It is from then on good for nothing.' Once men have lost the salt of a truly godly life they may witness all they like, but they will achieve nothing lasting.

‘Trodden under the foot of men.' The phrase indicates disdain and contempt, or, even worse, being totally ignored. Once the church is ignored it is a sign that it has lost its savour. The picture is probably that of being tossed out as rubbish into the streets, to be later collected by the rubbish collectors, but meanwhile walked over by all. It has. however, been pointed out that such salts were used in strengthening the flat roofs of houses, with the result that people would then trample it under foot. But this is probably becoming too sophisticated.

Jesus regularly uses the illustration of salt, and it would simply be being pedantic to suggest that they must all have been said at the same time just because of the mention of salt. Consider Mark 9:50; Luke 14:34; see also Mark 4:21; Luke 8:16; Luke 11:33. But there is little real parallel and no reason for therefore suggesting that they are the same saying taken up and used in a different context. The picture was such a useful one that He must literally have used it scores of times in different ways. The unfortunate impression given by some scholars, in their eagerness to discern what Jesus might actually have said, which results in their trying to find a core in a number of sayings, is that Jesus simply went around making inane comments, and all the interesting expansions came from the later interpreters, who were all moral geniuses.