At that time: It came to pass, as Jesus went to Jerusalem, that he passed through the midst of Samaria and Galilee. And as he entered into a certain village, there met him ten men that were lepers.
St. Augustine the Bishop
The ten lepers lifted up their voices and said: Jesus, Master, have mercy on us. And when he saw them, he said unto them: Go, shew yourselves unto the priests. And it came to pass that, as they went, they were cleansed. Question: Why did the Lord send them unto the priests, that, as they went, they might be cleansed? Lepers were the only class among those upon whose bodies he worked mercy, whom we find that he sent unto the priests. Thus it is written that he said to a leper whom he had cleansed: Go, and shew thyself to the priest, and offer for thy cleansing, according as Moses commanded, for a testimony unto them. We ask then, of what was leprosy a type, whereof they that were ridded of the same were said, not to have been healed, but rather, to have been cleansed. Leprosy is a disease which doth first appear in the skin, but destroyeth not immediately the strength, nor the use of feeling and the limbs.
By lepers, therefore, we may not unreasonably suppose such to be figured as have not the knowledge of the true Faith, but do shew forth divers parti-coloured teachings of error. They hide not their witlessness, but do use all such wit as they have to make it manifest, and proclaim it in high-sounding phrases. There is no false doctrine but hath some truth mixed up with it. A man's discourse then, with some truths in it unequally mingled with falsehoods, and all confounded in one mass, is like to the body of one that is stricken with leprosy, whereon all manner of foul colours do appear in this and that place along with the true colour of the skin.
Such men as these are banished out of the walls of the Church, to the end that haply when they stand afar off they may lift up their voices and to cry to Christ for pardon, just as those ten men that were lepers, which stood afar off, outside the village, lifted up their voices and said: Jesus, Master, have mercy on us. That they styled him Master, (by which title I know not if any others are said to have besought the Lord for bodily healing,) doth sufficiently shew (or so I think) that leprosy signifieth false doctrine, whereof the Good Master doth cleanse us.