John Gills Exposition of the Bible Commentary - Leviticus 13:40
And the man whose hair is fallen off his head ,.... That is, from the back part of his head, from the crown of his head toward his neck behind: he is bald ; in that spot of the head where the hair is fallen off; and it denotes such a baldness as is occasioned by that, for it signifies one that had hair, but it is fallen off; whereas the baldness after spoken of is thought by some to be of such who never had any hair; though others will have it, that this intends a person bald all over;... read more
Matthew Henry's Complete Commentary - Leviticus 13:38-46
We have here, I. Provisos that neither a freckled skin nor a bald head should be mistaken for a leprosy, Lev. 13:38-41. Every deformity must not forthwith be made a ceremonial defilement. Elisha was jeered for his bald head (2 Kgs. 2:23); but it was the children of Bethel, that knew not the judgments of their God, who turned it to his reproach. II. A particular brand set upon the leprosy if at any time it did appear in a bald head: The plague is in his head, he is utterly unclean, Lev. 13:44.... read more