Numbers 5:1-4

Unclean Persons
The Lord spoke to Moses, saying: Command the Israelites to put out of the camp everyone who is leprous, or has a discharge, and everyone who is unclean through contact with a corpse; you shall put out both male and female, putting them outside the camp; they must not defile their camp, where I dwell among them. The Israelites did so, putting them outside the camp; as the Lord had spoken to Moses, so the Israelites did.