is to be cleansed = him that is cleansing himself.
birds, or sparrows.
cedar wood, and scarlet, and hyssop. Hence the ancient tradition that the highest tree and the lowest herb give the leper purity, because pride was the cause of the plague, and humility is the necessary condition of its cure. These three were used also with the red heifer (Num_19:6). Compare Heb_9:19. Psa_51:7.