Tazria - Rishon
It’s Not Leprosy
Next, G-d spoke to Moshe about various forms of ritual impurity. When a woman has a baby boy, she will be impure for seven days; the baby's bris (circumcision) is on the eighth day. Her vaginal blood is considered ritually clean for 33 days after the seven, so if she bleeds, it does not restart the clock on her impurity. After this period of time, she will be considered purified. Until then, she cannot enter the Mishkan or touch sanctified things.
If she has a baby girl, the time periods are doubled: she is ritually impure for 14 days, followed by 66 days in which her blood is considered clean. After the 40 days (for a boy) or 80 days (for a girl), the woman brings a korban olah of a sheep and a korban chatas of a bird. If she can't afford the sheep, a bird may be substituted. (Why does the woman bring a korban chatas, which is a sin offering? The natural reaction of a woman in labor is "I'm never going through THAT again!" but she gets over it. This sacrifice is to atone for such a vow, which will not be kept. See Talmud Niddah 31b)
Next, the Torah discusses tzaraas, commonly translated as leprosy. Tzaraas was a spiritual ailment, the standard punishment for speaking lashon hara (gossip) and it is NOT what we would call leprosy. (I tried, but I just can't bring myself to use the common terms "leprosy" and "leper" here, so we'll just say "tzaraas" for the condition and "metzora" for the affected person.)
G-d instructed Moshe that when a person has a white, leprous-looking spot on his skin, he should be taken to a kohein. (Why a kohein and not a doctor? Because it's a spiritual disease, remember?) If the kohein determines that the hair in the affected area has turned white and that the mark goes beneath the surface of the skin, he will declare it impure then and there. If not, the kohein will quarantine the patient for a week, then re-examine him. If the mark hasn't changed, they'll give it one more week.