When good news arrives there are two things happen in our heart. They are feelings of joy and the urge to share the joy. When the joy is so great our heart finds it hard to contain it and it needs to be shared with friends and when share joy it is increased and spreads further. The leper had suffered greatly because of his skin disease and his own community disowned him. Jesus restored the man's health to wholeness and told him to keep quiet but to show himself to the priest as a sign of being welcomed back to his community- to regain his status. The healing gave so much joy to his heart and it was hard for him to keep quiet and as a result the leper disobeyed Jesus. His disobedience causes Jesus some trouble.
Jesus could no longer go openly into any town, but had to stay outside in places where no body lived. Even so, people from all around would come to Him. V.45
Jesus told the leper to keep quiet because he didn't know about Jesus. There is a real misconception of Jesus and his mission. What people expected Him to be and to do was quite different from what Jesus came to be and to do. The people expected Jesus to be their king and leader who would liberate them from the power of the Roman Empire. However, Jesus' mission was to bring us back to the Light from darkness, and set us free from the power of sin and submit ourselves to obey God.
The timing of when to reveal the identity of Jesus is set by God, not by the evil spirit or human beings. God alone decides how and when to reveal the identity of Jesus. Today we know the right time to reveal the real identity of Jesus and His mission was Post Easter, after His resurrection from the death.
Probably some people who knew the leper before saw he was cured and they would be happy in joining him to spread the good news while the onlookers were astonished and surprised to see the man. Jesus' ministry was not only cured the leper but brought him back to the community he once belonged to and gave him faith. What he brought back to the community was the sign of being healed completely and the sign of normalization. We are not surprise to know that God will not always respond to our prayers for physical healing but God never said no to any repentant heart in faith. The curing of our physical afflictions was the demonstration of the power of God over sickness and evil spirits but the primary of His mission was to save us from our sins and from eternal damnation. Remember we ask God for healing and the power to grant it is in the hand of the God the Giver not we, a receiver.