In Scripture there are two sorts of hard heart. In Pharaoh's case his hard heart led him to defy God. This was also the case with the wilderness generation who refused to enter the Land because of the spy's bad report. The disciple's hard hearts were if a different character. When faced with a storm on the sea, their life experiences and fear prevented them from realizing the power that Y'shua had given them. They tried to solve their problem by worldly means and failed.