Cleansing of the Ten Lepers and the Thankful Samaritan (Lk. 17: 11-19)
Jesus sends the lepers to the priest to be cleansed spiritually because this is what the law demands and in sending them He sends the healing; for they were made clean on the way (Cyril).
The Samaritan responds Jesus by thanking Him. The others thought more highly of their cure from leprosy than of Him who had healed them. Actually, the Samaritan was given much more than the rest. Besides being healed by his leprosy, he was told by the Lord, “stand up and go on your way; your faith has saved you” (Athanasius).
The nine lepers that were Jews did not return to give glory to God. Israel was hard of heart and utterly thankless. The Samaritan was grateful (Cyril).
The Jews, even when they benefited, were ungrateful.