Leviticus - Chapter 13

In this chapter there are regulations concerning a person with an infectious skin disease. Where the priest confirms that the person has this disease the person is unclean:

"Those who suffer from a serious skin disease must tear their clothing and leave their hair uncombed.  They must cover their mouth and call out, ‘Unclean! Unclean!’ As long as the serious disease lasts, they will be ceremonially unclean. They must live in isolation in their place outside the camp."

Living outside the camp they cannot bring an offering to the Tabernacle and are therefore not able to come to God.

Jesus came to restore "unclean" people to God, and the first miracle described in the New Testament deals with this (in Matthew 8):

"A leper came and worshiped Him, saying, “Lord, if You are willing, You can make me clean.” Then Jesus put out His hand and touched him, saying, “I am willing; be cleansed.” Immediately his leprosy was cleansed."