I believe the basis for your question comes from Matthew 8:1-4, “When he was come down from the mountain, great multitudes followed him. And, behold, there came a leper and worshipped him, saying, Lord, if thou wilt, thou canst make me clean. And Jesus put forth his hand, and touched him, saying, I will; be thou clean. And immediately his leprosy was cleansed. And Jesus saith unto him, See thou tell no man; but go thy way, shew thyself to the priest, and offer the gift that Moses commanded, for a testimony unto them.”  In this instance, we see the Lord Jesus miraculously healing a man with leprosy.  Notice that the Lord actually touched this man.  The Lord Jesus, because of His intrinsic holiness and purity could not be affected by this man’s leprosy, although this Biblical leprosy was highly contagious.  The word ‘gift’ refers to a ‘sacrificial gift.’  The Greek word for ‘gift’ is translated as ‘offering’ in Luke 21:4. Because the Old Testament law was still in effect at that time, there were certain obligations for the healed leper to perform. 

To say that this gift was what “Moses commanded” is referring to the Law that the Lord gave through Moses.  Leviticus 14 gives us the “Law of the Leper” showing the steps that must be taken by one who had been healed from his leprosy.  There were certain ceremonial rituals that had to be accomplished in order to pronounce this healed leper as clean.  Here in Leviticus 14, God gave Moses instructions on how to handle lepers that were healed. In this passage, a ceremonial cleansing was performed by the priest…two birds, cedar wood, scarlet, water, and hyssop were used. A bird was sacrificed, and the blood was applied to other elements and another bird that was alive. The person healed from leprosy was sprinkled along with a living bird that was then turned loose into a field. The person was pronounced clean and was sent to his tent inside the camp to wait for a week. After the week was completed, he was commanded to make a sacrifice that consisted of a trespass offering and a sin offering, a burnt offering, and a meal offering (Verses 10-20).

Once completed, the priest would go to the person’s house and command it to be cleaned. A week later he would return and if the house was not clean, he would command that the unclean parts be removed and replaced. If that did not work, then he would have the house demolished and the rubble removed to outside the camp. If it remained clean, a sacrifice for the house was performed much like the one done for the person.

It is in Leviticus 13:38-44, we read of the characteristics and symptoms of the leper.  Then we read in Leviticus 13:45-46, “And the leper in whom the plague is, his clothes shall be rent, and his head bare, and he shall put a covering upon his upper lip, and shall cry, Unclean, unclean. All the days wherein the plague shall be in him he shall be defiled; he is unclean: he shall dwell alone; without the camp shall his habitation be.”  Leprosy was highly contagious and so the leper was to separate himself from all the others, and if he came into close proximity to others, he was required to shout, “Unclean, unclean” to warn people to stay away from him. 

Because of lack of space, we will not go over all the rituals that had to be performed before this healed leper could be declared clean, but I greatly encourage you to read Leviticus 13 and 14 to learn more.

The main reason why leprosy is talked about so much in the Bible is that it is a striking illustration of sin’s destructive power in us. In ancient Israel, leprosy was a powerful object lesson of the devastating influence of sin in a person’s life.  To be healed and cleansed of leprosy required death and the shedding of blood.  Certainly, this is a type of how Christ died and shed His blood to take away the sins of the world as we read in 1 John 2:1-2, “My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous: And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world.”  My friend, have you realized that you are a sinner and that you cannot rid yourself of your sin.  You need a savior.  You need someone who can pay your sin debt by dying for you and paying that debt you owe but cannot pay.  That, my friend, is the Lord Jesus Christ.  Speaking of Christ, we read in Colossians 1:14, “In whom we have redemption through his blood, even the forgiveness of sins.”  How do you receive Him as your savior and receive the forgiveness of sins?  Romans 10:9 says, “That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.”  (CC)  (544.3)