Albert Barnes on Luke 10:33

A certain Samaritan. The Samaritans were the most inveterate foes of the Jews. They had no dealings with each other. Mt 10:5. It was this fact which rendered the conduct of this good man so striking, and which was thus set in strong contrast with the conduct of the priest and the Levite. They would not help their own afflicted and wounded countryman. He, who could not be expected to aid a Jew, overcame all the usual hostility between the people; saw in the wounded man a neighbour, a brother, one who needed aid; and kindly denied himself to show kindness to the stranger.

(k) "Samaritan" Jn 4:9