'Understand' in the Bible

He supposed that his brothers understood that God, by his hand, was giving them deliverance; but they didn't understand.

Philip ran to him, and heard him reading Isaiah the prophet, and said, "Do you understand what you are reading?"

"Those who were with me indeed saw the light and were afraid, but they didn't understand the voice of him who spoke to me.

saying, 'Go to this people, and say, in hearing, you will hear, but will in no way understand. In seeing, you will see, but will in no way perceive.

For this people's heart has grown callous. Their ears are dull of hearing. Their eyes they have closed. Lest they should see with their eyes, hear with their ears, understand with their heart, and would turn again, and I would heal them.'