Let’s see the story of the ten lepers in Luke 17:11-18
11 Now it happened as He went to Jerusalem that He passed through the midst of Samaria and Galilee.
12 Then as He entered a certain village, there met Him ten men who were lepers, who stood afar off. 13 And they lifted up their voices and said, “Jesus, Master, have mercy on us!”
14 So when He saw them, He said to them, “Go, show yourselves to the priests.” And so it was that as they went, they were cleansed.
15 And one of them, when he saw that he was healed, returned, and with a loud voice glorified God,
16 and fell down on his face at His feet, giving Him thanks. And he was a Samaritan.
17 So Jesus answered and said, “Were there not ten cleansed? But where are the nine?
18 Were there not any found who returned to give glory to God except this foreigner?” 19 And He said to him, “Arise, go your way. Your faith has made you well.”
While Jesus was on his way to Jerusalem, ten lepers came to him, which, keeping their distance, shouted to him to have mercy on them. At that time the law required that the people suffering from this disease to live in isolation, so they kept their distance from Jesus when they could see it. Jesus immediately ordered them to appear before the priests. Why did Jesus command them this? For when a leper was healed, the priest examined him and declared healthy (Leviticus 13: 9-17).
In an act of faith, the ten lepers, even without being healthy, went to the priests. Thanks to their faith, they were healed on their way to the priest. And only one of them feeled grateful and returned, not only to thank Jesus, but also to glorify God with a loud voice. The odd thing is that the only one who returned to give thanks was a foreigner.