"You are the salt of the earth, but if salt has lost its taste, how shall its saltiness be restored?" [Matt 5:13] It is as if the apostles were asking to whom he was speaking all these things, whether generally to the people or to them, and Christ, wishing to show them that he was chiefly speaking these things to them, added, "You are the salt of the earth." That phrase "you are the salt of the earth" points to that which he said before, namely, that a teacher ought to be adorned with all virtues. He ought to be poor in order to rebuke greed with a free voice. He ought to be sighing and grieving, whether for his own sins or those of others, in order to confound those who do not hesitate to sin before they sin or are sad because they have sin after they have sinned. He should so sigh and weep in order to show thereby that the world is a grave and dangerous place for the faithful. He ought to hunger and thirst for righteousness in order by the word of God or the scourge of rebuke to be strong to stir up the idle toward good works or at least reading faithfull - more by example than by his voice. He ought to be accustomed to rule the church more by forgiving than by punishing so that he may be loved more than feared. He ought to be merciful to others but strict with himself, so as to put the heavy burden on others. He ought to be pure in heart so that he does not get himself involved with wordly business but not even think about the world. Just as the eye becomes purer the longer it sees, so also the further a soul is from worldly trouble the more fully it is closer to God. But if the eye of a person's heart gazes at the world, his mind cannot see God. Let him be a peacemaker so that his whole church may be of one mind. But where there is no harmony, neither is prayer heard nor is the sacrifice accepted because neither is God there where disharmony reigns. He ought to also be ready to suffer, not having the vain hopes of martyrdom but the constancy of faith worthy of the marytyrs. For as far as the wise are concerned, that soldier is not said to be prepared for war who desires to go out to fight, but rather he who is able to go out. Thus, if he has been adorned with all these virtues, then he is very good salt, and all the people are edified from him more by seeing him than hearing him. For the first teaching is to see a good person, and the second is to hear him. "You are the light of the world." [Matt 5:14] While we consider what is the function of salt and that of light, he admonishes to seek the reason the apostles were compared with salt and the reason they were compared with light. It is the function of salt to preserve an object in the state in which it is found it so as not to allow it to be changed for the worse, but salt cannot make it better. For example, it preserves meat from spoiling, but it cannot make spoiled meat fresh. It is the function of light to break up the darkness and to light up those things that were in darkness. So also the apostles and other teachers are the salt of the Christian people who already know God, since they preserve them in their very knowledge of God and holiness, that is, they are the salt of the cultivated land, which has been subjected to the word of the cross as to the tiller and the plow. But they are the light of the heathen, bringing them to the light of knowledge, or the light of others who by chance have fallen in the church in the darkness of their sins. Again, the priest's good manner of life without a word keeps them holy in holiness through his own example, but it cannot lead the ignorant to knowledge of the truth. Again, the word can lead the ignorant to knowledge of the truth even without a good manner of life, but to keep them in faith or holiness cannot be done without a good manner of life, but rather he also scandalizes them, as we will show below. Therefore fo the sake of their good lifestyle the priests are salt because the priests' good manner of life is the preservation of the people. Because of the word of doctrine they are light because the word is light to the ignorant. First he called them salt, afterwards light, either because it is the first priority to preserve what you have and it is the second priority to call those whom you do not have, or because living well comes first, and then teaching well. For through a good manner of living one can ascend without doubt to knowledge, but from knowledge I do not know if one can altogether come to a good manner of living. For that reason we see many knowledgeable people without the fear of God, but we do not see those who do not fear God without having any knowledge. Or because of the Jews they are first said to be salt, since they did not lead them to the knowledge of God but preserved them in that knowledge. They are light, however, because of the Gentiles who were called in the second place. Consequently, introducing the matter through an apt comparison, he adds, "A city put on a hill cannot be hidden." Although it might wish to be hidden, the mountain itself that carries it makes it clear to all. So also the apostles and priests who have been founded on Christ, the lofty mountain, are not able to be hidden; and if they wished to hide themselves, Christ reveals them, since he carries them. What is this city? It is the church of the saints, concerning which the prophet says, "Glorious things are spoken of you, O city of God." [Ps 83:7] Its citizens are all the faithful, concerning whom the apostles says, "You are fellow citizens with the saints and members of the household of God." [Eph 2:19] Its towers are the prophets, about whom it is written, "Peace be withing your walls, and security withing your towers!" [Ps 122:7] Just as arrows are fired from the towers against all the enemies, so from the prophetic books salutary examples of the truth are set forth against the idle tales of the heathen and the mad disputations of the heretics. Its gates are the apostles, concerning whom it is written: "The Lord loves the gates of Zion more than all the dwelling places of Jacob," [Ps 87:2] because through them all the people enter into faith. Its walls are the priests and other teachers, concerning whom the prophet says to this spiritual Jerusalem, "Foreigners shall build up your walls," [Is 60:10] because once they were called from the Gentiles, they were made priests and rulers of the church. Just like walls, they take every arrow of the heathen and of the heretics, who strike the clergy, that is, the wall of the church, with frequent persecutions as with battering rams. And just as walls receive deadly arrows, so the teachers like living stones receive the mad words of their perverse thought, which proceed from the impious quiver of the heart; and like walls the teachers bind the church together by the virtue of faith. Therefore this city has been placed on top of a mountain; that is, the apostles, prophets and other teachers have been built in Christ. The mountain is Christ, concerning whom Daniel says, "As you looked, a stone was cut out by no human hand, and it ... became a great mountain and filled the whole earth." [Dan 2:34-35]

 

(trans. Kellerman 2010: 89-91)