In the gospels the Samaritans are generally depicted very favourably. The leper who came back to thank Jesus was a Samaritan (Luke 1:11-19) and the Samaritan woman at the well, in in chapter 4 of John, was sent as an apostle to her people. In this story too, the hero of the story is a Samaritan. This would have startled Jesus’ audience. The Samaritans and the Jews loathed one another. The Northern Kingdom of Israel fell in the eight century BC to Assyria and the people intermarried with Assyrians. When they returned home they built their temple at Mount Gerazim and disagreed with the Jews on scripture. Such was their animosity towards each other that the Samaritans poured pigs’ blood around the temple that the Jews were rebuilding and in the second century BC the Jews destroyed the temple at Gerazim.
Both the lawyer who questioned Jesus and the priest and Levite would have been strict observers of the law but it did not stir the latter into compassion for the wounded man. The command of Leviticus (19:18) was to “love your neighbour as yourself.” They probably interpreted neighbour as someone in a close relationship. They may have worried about becoming ritually unclean by coming in contact with blood or being attacked by robbers, who had plenty of hiding places on the road to Jericho. The Samaritan, on the other hand, saw only a fellow human being in distress and did all he could to help him. The wine would have disinfected the wounds and the oil would have soothed them. Neither of these commodities was cheap. Two denarii would have been a couple of days' wages.
Jesus acted as the Good Samaritan all his life. He reached out to Romans, the unclean, Samaritans, the marginalised and in the end to the thief on the cross.