The spotless lamb takes the place of the unclean.
We hear in the first reading today of the Lord's instructions to Moses and Aaron regarding those afflicted with leprosy. The Lord says,
The one who bears the sore of leprosy shall keep his garments rent and his head bare,
and shall muffle his beard; he shall cry out, 'Unclean, unclean!' As long as the sore is on him he shall declare himself
unclean, since he is in fact unclean. He shall dwell apart, making his abode outside the camp.
Thus, those individuals were to visibly identify themselves by keeping their garments rent, head bare and beard muffled. They also had to audibly identify themselves as well with the unwelcome identifier "Unclean." Finally, the leper was to separate himself, physically from the rest of the group by living outside the camp.
In the gospel reading we hear of Jesus' healing of the leper. The leper, in his act of faith, comes to Jesus and confidently asserts,
If you wish, you can make me clean.
Jesus touches the unclean man and makes him clean. Jesus then gives the man two instructions. First, Jesus tells the man to not tell anyone of this. I'll come back to this point later. Jesus also tells the man that he should show himself to the priest and fulfill the proper offering which Moses prescribed for those made clean. It is interesting to note that the purification offering is quite elaborate as described in
Leviticus 14. The offering includes the following prescription...
Taking one of the male lambs, the
priest shall present it as a reparation offering,
along with the log of oil, raising them as an elevated offering
before the Lord.
Getting back to Jesus' first instruction to the man made clean. Jesus, as he does after many of his miraculous cures, told the man not to tell anyone anything. However, the man could not contain himself and publicized the whole matter. Word traveled and as a result Jesus was mobbed when he tried to enter any town. As such, Jesus ended up staying outside of the towns. It is as if Jesus traded places with the man who would have had to remain outside of town himself. The spotless lamb takes the place of the unclean.