This question reflects the ancient Jewish belief that sin caused all illnesses and other deformities. The rabbis also taught that it was possible for a baby to sin while still in the womb. Alternate translation: "Teacher, we know that sin causes a person to be blind. Whose sin caused this man to be born blind? did this man himself sin, or was it his parents who sinned?" (See: [[rc://en/ta/man/translate/figs-explicit]])