"He looked around at them with anger; he was grieved at their hardness of heart..."
What got Jesus angry? Unbelief? Doubt? Sin? Nope. He could deal with all those things. He had boundless patience & grace for those struggling with that. What really seemed to tick him off was lack of compassion (aka "hardness of heart").
There's a story in Mark 3 where Jesus was at a synagogue on the sabbath. He saw a man who had a withered hand. Jesus knew some were waiting for him to do something "improper" - like healing on the Sabbath (which was considered "work," so it was forbidden on the Sabbath). So before he did anything, Jesus asked a simple question: "Is it lawful to do good or do harm on the Sabbath?" Despite all of the Sabbath regulations & restrictions, the bottom line was to DO GOOD! But his detractors couldn't admit this and still hope to entrap Jesus. So they said nothing.
What struck Jesus was their lack of compassion for the man injured. They were more concerned about their destructive plans for Jesus than about this man's personal pain. Their hearts were hard.
Sometimes we get caught up in our own "stuff" (plans, agendas, daily routines, etc.) that we miss the needs of a hurting world around us. God forbid that we allow our hearts to become hardened beyond softening! God forbid.