There was a scholar of the law who stood up to test Jesus and said, "Teacher, what must I do to inherit eternal life?" Jesus said to him, "What is written in the law? How do you read it?" He said in reply, "You shall love the Lord, your God, with all your heart, with all your being, with all your strength, and with all your mind, and your neighbor as yourself." He replied to him, "You have answered correctly; do this and you will live." But because he wished to justify himself, he said to Jesus, "And who is my neighbor?" (Lk 10:25-37)
https://bible.usccb.org/bible/readings/071022.cfm
Who is my neighbor? Well, what follows is the Parable of the Good Samaritan. Of course, Jesus turns the world upside down and ruins a perfectly good anti-clerical joke (the priest and the levite ignore the man in the ditch) by having the man’s enemy (the Samaritan) be the one who saves his life.