Theophylact of Ohrid

By salt the Lord also means the apostles, and in general those who have a preserving and binding power. For just as salt preserves meat and does not allow worms to breed in it, so too the word of a teacher, if it is strong and astringent, restraining people from fleshly passions, does not give place in them to the sleepless worm. But if the teacher himself is without salt and does not have within himself a stimulating and binding power, with what shall he be salted, that is, corrected? …

Commentary on Mark ↗

Methodius of Olympus

For as the putrid humours and matter of flesh, and all those things which corrupt it, are driven out by salt, in the same manner all the irrational appetites of a virgin are banished from the body by divine teaching. For it must needs be that the soul which is not sprinkled with the words of Christ, as with salt, should stink and breed worms, as King David, openly confessing with tears in the mountains, cried out, "My wounds stink and are corrupt," because he had not salted himself with the exercises of self-control, and so subdued …

The Banquet Of The Ten Virgins 1.1 ↗

Gregory the Dialogist

But, when the ruler prepares himself for speaking, let him bear in mind with what studious caution he ought to speak, lest, if he be hurried inordinately into speaking, the hearts of hearers be smitten with the wound of error and, while he perchance desires to seem wise he unwisely sever the bond of unity. For on this account the Truth says, "Have salt in yourselves, and have peace one with another." Now by salt is denoted the word of wisdom. …

The Book of Pastoral Rule, Part 2, Chapter 4 ↗

Bede

Good salt. But if the salt becomes insipid, with what will you season it? It is good to hear the word of God more frequently, to season the secrets of the heart with the salt of spiritual wisdom, indeed to become the salt of the earth with the apostles themselves, that is, to suffice for the minds of those still wise in earthly matters to be saturated. …

On the Gospel of Mark ↗