We are not told how the leper knew he could come to Jesus nor why he should want to come to Jesus. The assumption is that he had heard of the miracles that Jesus had already performed (Matthew 4:23) and decided that since Jesus had helped others he could help him as well. Such a deduction is part of the logic of saving faith because it learns from the experience of others. He had heard that others had been helped by Jesus and therefore was optimistic that he would help him also.
The leper’s approach to Jesus shows to us how a sinner should come to Jesus for mercy. First, he acknowledged that Jesus was divine. It would be possible to suggest that the title ‘Lord’ was only one of respect, yet when combined with his action of kneeling we can see that the leper recognised that Jesus was the promised Messiah. Here we have an example of God’s amazing grace in which he enlightens an unexpected person to confess the superiority of Jesus.
At the same time, the leper expressed his submission to Jesus when he focussed on whether or not the Lord was willing to help him. Of course, the leper is not suggesting that Jesus would be reluctant to heal. Instead he is expressing his conviction that Jesus is sovereign even in how he chooses to help needy people. The leper recognised that he was not in a position to make demands of Jesus. And we must come to that realisation. Desperation is not a valid reason for disrespect.
The leper’s confession also highlights his spirituality. After all, he did not ask Jesus to heal him. Instead he asked Jesus to make him clean. His focus on cleansing informs us he wanted to worship God in the temple with his people. If all that he wanted was to be able to go in and out in the community, he only needed physical healing. But he also wanted to be right with God, which tells us that there was a spiritual desire in his request.
His grasp that he needed cleansing points to the reality that he recognised that he was a sinner. So we can deduce that in his request there was an expression of repentance. This recognition can also be seen in his awareness that Jesus was divine. Why else would he have gone to Jesus for help?