Then Jesus answered, “Were not ten cleansed? Where are the nine?
We have here an account of the cure of ten lepers, which we had not in any other of the evangelists. The leprosy was a disease which the Jews supposed to be inflicted for the punishment of some particular sin, and to be, more than other diseases, a mark of God's displeasure; and therefore Christ, who came to take away sin, and turn away wrath...
Commenting on Luke 17:11-19
There are not found that returned,.... Or it do not appear, that any have returned: to give glory to God; for inasmuch as they did not return to give thanks to Christ, and acknowledge him the author of their cure and cleansing they did not give glory to God: save this stranger; for so the Samaritans were reckoned by the Jews, even as the Gentile...
Verses 17,18. Where are the nine? Jesus had commanded them to go to the priest, and they were probably literally obeying the commandment. They were impatient to be healed and selfish in wishing it, and had no gratitude to God or their Benefactor. Jesus did not forbid their expressing gratitude to him for his mercy; he rather seems to reprove them for not doing it.