17:17 where are the nine. The Lord takes note of both those who thank Him and those who do not. Compare Luke 7:44-46. He actually seeks those who will worship him (John 4:23).
17:18 this stranger. The one thankful ex-leper was a Samaritan (Luke 17:16), just as the caring traveler in Jesus’ parable of the good Samaritan (Luke 10:33). Jesus also went out of His way to speak to the Samaritan woman at the well (John 4:9) and to instruct His apostles to witness to the Samaritans as well as the Jews (Acts 1:8).