In this chapter, Yeshua will engage the Pharisees on their observance of meaningless traditions and rituals that are outside of Torah. In this passage, the Pharisees were insisting on the disciples performing the traditional hand washing that they made a part of their Jewish laws.
Yeshua and His disciples were walking through the grain fields on the Sabbath and they were hungry. They plucked heads of grain and ate them. It is perfectly lawful to do so (Deut. 23:24-25). We are told in Luke’s account that they were rubbing them with their hands in order to remove the chaff from the grain (Luke 6:1). The Pharisees apparently interpreted this to be the equivalent of threshing and winnowing the grain, which is ridiculous.
This man took a great chance in coming up to Yeshua because lepers are to stay away the people and signal to them when he was around (Lev. 13:45-46). But this man apparently kept himself covered up and came up to Yeshua without them knowing he was a leper. It is likely that Yeshua made sure that He came near the dwelling of this leper when He came down from the mountain. This man demonstrated faithfulness that Yeshua was Messiah. He said that He knew Yeshua could make him clean.