Two cases are mentioned which the priest is not to regard as leprosy. The first (vv. 12, 13) is that in which the plague "covers all the skin of him that hath the plagues from his head even to his feet, as far as appeareth to the priest," so that he "is all turned white." At first thought, this seems quite unaccountable, seeing that leprosy finally affects the whole body. But the solution of the difficulty is not far to seek. For the next verse provides that, in such a case, if "raw flesh" appear, he shall be held to be unclean. The explanation of this provision of ver. 12 is therefore apparently this: that if an eruption had so spread as to cover the whole body, turning it white, and yet no raw flesh had appeared in any place, the disease could not be true leprosy; as, if it were, then, by the time that it had so extended, "raw flesh" would certainly have appeared somewhere. The disease indicated by this exception was indeed well known to the ancients, as it is also to the moderns as the "dry tetter;" which, although an affection often of long duration, frequently disappears spontaneously, and is never malignant. The second case which is specified as not to be mistaken for leprosy is mentioned in vv. 38, 39, where it is described as marked by bright spots of a dull whiteness, but without the white hair, and other characteristic signs of leprosy. The Hebrew word by which it is designated is rendered in the Revised Version "tetter;" and the disease, a non-malignant tetter or _eczema_, is still known in the East under the same name (_bohak_) which is here used. Verses 45, 46, give the law for him who has been by the priest adjudged to be a leper. He must go with clothes rent, with his hair neglected, his lip covered, crying, "Unclean! unclean!" without the camp, and there abide alone for so long as he continues to be afflicted with the disease. In other words, he is to assume all the ordinary signs of mourning for the dead; he is to regard himself, and all others are to regard him, as a dead man. As it were, he is a continual mourner at his own funeral.