I was just reading through Leviticus 13:1-46 and was amazed by the instructions God gave the people for their own good. First, He is aware that no real medical advancements have been made so He tells the priests and people exactly what to do look for to tell if a skin condition goes deeper than the skin (they look for hair in the affected area). He also gives the people many opportunities for healing checks so that they aren't unclean for too long if their disease is just a temporary ailment. Everything makes a lot of sense health wise and shows how God cares for His people but Leviticus 13:45-46 always makes me cringe. It seems a little unnecessary for the people to have to tear their clothes, leave their hair uncombed, cover their mouth and yell "unclean", and live in an isolated place outside the camp. But when you really think about it, it's not.
The part that's the hardest for me to grasp is living out side of the camp, especially since leprosy (now called Hansen's disease) is not very contagious.* It can only be caught through respiratory droplets (someone breathing on you) of an infected person. And now it makes sense. If you have this disease it would foolish to stay in camp, even if you were confined to your home. In Biblical times, many families all slept together and married couples certainly did. If you had the disease, there was a huge chance that you'd breath on someone while y'all were sleeping and then you'd both have it!
The clothes and hair and yelling fulfill the need for a visible, audible sign so that no one unwittingly come close enough to catch the disease. And, just incase, God has them cover their mouths as they yell (could this be to catch any sneaky respiratory droplets?). So, point is, when you take a closer look a Biblical rules and passages that seem ridiculous, you discover that they actually make perfect sense and Leviticus 13 is no exception! :)
*My study Bible also said that leprosy could have simply been the name used for all the skin diseases since they couldn't differentiate between them yet and Hansen's Disease was the most common one or something like that. In this case, it is likely that many types of "leprosy" were contagious. But for now, lets leprosy is referring to Hansen's Disease.