“When a person has on the skin of his body a swelling or an eruption or a spot …” (13:1). Without antibiotics, surgery, or hospitals, ancient people were always at risk of a disease quickly spreading through an entire community. In this case, the Israelites had regulations about different kinds of rashes, white spots, sores, etc, focusing on identifying the worst kinds (including leprosy) and isolating the person in order to prevent a group outbreak. Only a priest could pronounce someone “clean” and welcome them back into society.
Instead of withdrawing in fear, Jesus touched the unclean person and healed him. His own goodness and power is enough to bring wholeness to any situation we face.