Luke 17:12

And as He entered into a certain village. Lepers, as being unclean, were not able to enter cities, towns and villages, lest they should communicate their leprosy to the inhabitants, as well as their legal defilement, which under the old law was communicated by contact with a leprous and unclean person; as in Numbers 5:2. Hence they met Christ before the village.

There were ten lepers, says Euthymius, whom their disease had united together; for otherwise the Jews hold no communication with the Samaritans, John 4:9. These ten leper's seem to have agreed, as soon as they met Jesus, to demand to be healed with one voice. They made an attack upon the clemency of Jesus.

They stood afar off, as being unclean and out of communion with the clean, being banished lest they should affect them by their breath. In figure leprosy is concupiscence, heresy, and every kind of sin, as is shown in Leviticus 13:14 xiv. and Matthew 8:2.