Then Jesus told him, “See that you don’t tell anyone; but go, show yourself to the priest, and offer the gift that Moses commanded, as a testimony to them.”
Matthew 8:4 (CSB)
Jesus had just healed a man with leprosy. God’s law, given through Moses, said that a person healed of leprosy had to show himself to a priest, who would examine him, and then go through the cleansing and offerings Moses commanded before he was fully restored (Leviticus 14).
A priest could only declare a person clean after the healing had happened. He had no power to make anyone clean. So a man standing before the priest with healthy skin would be living proof, a “testimony,” of what Jesus had done.
Mark’s Gospel tells us that the man disobeyed Jesus and told everyone, and because of that Jesus “could no longer enter a town openly” (Mark 1:45). Obeying Jesus matters more than doing what seems best to us, so we ought to do the plain things Jesus has told us, like making things right with someone we have wronged.
The offerings in the Old Testament pointed ahead to something far better. The Bible says that Jesus “offered himself without blemish to God” so that His blood would make our consciences clean (Hebrews 9:14). His death is the offering that makes us clean before God, and everyone who trusts Him is forgiven.