The pharisees were looking for every opportunity to negate the validity of Jesus as being the Messiah. In this particular incident, they took on the issue of Sabbath which is part of the ten commandments. The Pharisees took all the rules to the extreme while forgetting the very reason for which God created Sabbath in the first place.
After a hard night of fishing, Peter had returned to the shore disheartened, when he saw Jesus approaching. Jesus got into Peter’s boat and started to preach to the people gathered on the beach. Peter wrapped up his fishing gear and joined the others.