As the Israelites are traveling through the wilderness, the prophetess Miriam, Moses’ sister, is struck with an infectious skin disease for questioning her brother’s authority as the Lord’s representative (Numbers 12:1–15). Moses prays for her, and she is healed after a week. The allusion to this event seems intended to stress that God has complete power over diseases that cause impurity—both to strike people and to heal them—and that the Israelites therefore need to respect the authority of the Lord’s representatives, the priests, as they treat cases.