The colloquial phrase "good Samaritan," meaning someone who helps a stranger, derives from this parable.
The parable is found in the Gospel of Luke, chapter 10, verses 25-37.
The parable goes;
One day an expert in religious law stood up to test Jesus by asking him this question: "Teacher, what should I do to inherit eternal life?" Jesus replied, "What does the law of Moses say? How do you read it?" The man answered, "You must love the Lord your God with all your heart, all your soul, all your strength, and all your mind." And, "Love your neighbour as yourself.'" "Right!" Jesus told him. "Do this and you will live!" The man wanted to justify his actions, so he asked Jesus, "And who is my neighbour?"
Jesus taught this parable in order to get people to think for themselves, there but for the grace of God, go I, robbed, bashed, left on the side of the road. The Levite and the Priest cross the road in order to avoid being unclean. They do not help the man on the side of the road
A despised Samaritan came along, put the man on his donkey, bound his wounds, paid for his medical care, and offered to make good the accommodation charge on his return.
Jesus asks the question, "Who was this man's neighbour, the Levite, the Priest or the Samaritan?" The reply is 'The one who had mercy on him".
The point is, mercy and compassion come from the heart, and it is the heart where the seat of God is in man.