God tells the human race to go forth and multiply, but when Israelites do it, it's time to break out the spiritual Purell.
The writer opens this chapter with a fairly graphic description of how stuff flowing from a guy's penis can make a place unclean.
Got a—ahem—leaky faucet? Any bed, chair, or saddle you touch becomes unclean, not to mention folks who touch you.
They have to wash up and do laundry. You have to wash up and do laundry. After seven days of washing up and doing laundry, your friendly neighborhood priest gets to sacrifice a couple of birds.
The above rule applies to all sorts of penis leaks, such as masturbation, nocturnal emission, and the pus from gonorrhea. In short, men are gross.
God may be all-knowing, but at this point he's being rather coy about penicillin. Oh, wait, that's mold, isn't it? Wouldn't want that now, would we? Might make something unclean.
When a man and a woman are making sweet romance, they also become unclean. This means they both have to take a bath, which as purity rules go would seem to have an obvious loophole.
Do You Ever Feel, You Know, Not So Fresh?
The rest of this chapter has purity rules for dealing with menstrual flow.
A woman having her period is unclean for seven days. Everything she touches is unclean for the day, such as her chair and bed.
A guy who lies with her (wink, wink) during this time is unclean for seven days too.
If a woman's flow continues for more than seven days, she stays unclean until seven days after it stops.
On the eighth day? Birds, sacrifice, you know the drill.
Another Fine Mess
The chapter ends by zooming out to 30,000 feet to look at the bigger picture. Well, technically they don't have planes, so at best it's about 7,500 feet.
The reason for these rules? Once again, uncleanness anywhere in Israel makes the holy Tabernacle unclean: "thus shall they separate the children of Israel from their uncleanness: that they die not in their uncleanness, when they defile my tabernacle that is in the midst of them."