'Hearts' in the Bible

Right away Jesus understood in His spirit that they were thinking like this within themselves and said to them, “Why are you thinking these things in your hearts?

After looking around at them with anger and sorrow at the hardness of their hearts, He told the man, “Stretch out your hand.” So he stretched it out, and his hand was restored.

because they had not understood about the loaves. Instead, their hearts were hardened.

For from within, out of people’s hearts, come evil thoughts, sexual immoralities, thefts, murders,

But Jesus told them, “He wrote this command for you because of the hardness of your hearts.