The site I got this photo from says that leprosy is curable now, which is good. I read somewhere that is more rare to find in developed countries.
Verse 16-17 says that if the raw flesh changes into white, then the person goes to the priest and upon confirmation, the person is declared clean. Verses 18-19 describe that during leprosy the body can develop a boil with a white swelling or bright spot, reddish white. If this occurs then the person is to go see a priest. Verse 20 states if it is deeper than the skin, while the hair has turned white, then the person is unclean. It becomes known as a leprous sore that has broken out of its boil.
Verse 21 states if the priest finds no white hairs and the skin is not deeper than the skin and has faded then he isolates the person for seven days. Verse 22 If the boil spreads all over the skin during that time then the priest declares the person to be unclean. However, if it does not spread then verse 23 states it becomes a scar of the boil and the priest declares the person to be clean.
I don't know how long it took Moses to figure all this out, or if it was already well documented somewhere in ancient history. This type of knowledge seems dependent on the breakout of the infection from bacteria; some being more or less severe than others. With how the verses relate to if the person becomes unclean or not, it appears that these verses come from the inspiration of God. It doesn't really seem all that random here, like some later cultures that had witch doctors that performed rituals to try to cure you.
