Numbers 5:1-4

The Seclusion of Persons Rendered Unclean through Leprosy, Issues, or Contact with the Dead. Such seclusion was the result of a primitive belief that persons in the conditions specified were the seat of, or had been exposed to, some supernatural influence which they might extend to any who approached them. Rules relating to the leprous and to sufferers from issues are found in Leviticus 13-15*. For historical instances of the seclusion of lepers, see Numbers 12:10; 2 Kings 7:3; 2 Kings 15:5.

Numbers 5:2. the dead: literally, a soul or ghost. A dead body was thought to be dangerous because the disembodied spirit hovered round it, and such a spirit was potent for harm.