He had to tell Mark 1:40-45

A hurting man came to Jesus. Everyone could see his disease. He was a leper. The broken skin and open sours proved it to everyone around. He came to Jesus in faith. He didn't ask Jesus if he was capable of healing. Instead he pleaded with Jesus in faith bowing down before him,

If you choose, you can make me clean

Jesus responded to the hurting man's faith with a touch and words of healing. Only someone with power could do and say what Jesus did. Pity alone wouldn't heal him. A human touch alone wouldn't set him free. He needed Jesus to choose to act on his behalf.

Moved with pity, Jesus stretched out his hand and touched him, and said to him, ‘I do choose. Be made clean!’ Immediately the leprosy left him, and he was made clean.

The next words from the story surprise us. Jesus told them man sternly not to tell anybody except the priest about being made clean. But the didn't stay silent; he told story. The story he told and the story others told about Jesus spread. People came searching for him. They knew that he had the power to renew all things.