'Understand' in the Bible

This is the reason I speak to the crowds in parables: because while [having the power of] seeing they do not see, and while [having the power of] hearing they do not hear, nor do they understand and grasp [spiritual things].

In them the prophecy of Isaiah is being fulfilled, which says,‘You will hear and keep on hearing, but never understand;And you will look and keep on looking, but never comprehend;

For this nation’s heart has grown hard,And with their ears they hardly hear,And they have [tightly] closed their eyes,Otherwise they would see with their eyes,And hear with their ears,And understand with their heart, and turn [to Me]And I would heal them [spiritually].’

Then the righteous [those who seek the will of God] will shine forth [radiating the new life] like the sun in the kingdom of their Father. He who has ears [to hear], let him hear and heed My words.

Do you not understand that whatever goes into the mouth passes into the stomach, and is eliminated?

Do you still not understand or remember the five loaves for the five thousand, and how many baskets you picked up?

How is it that you fail to understand that I was not talking to you about bread? But beware of the leaven of the Pharisees and Sadducees.”

and they did not know or understand until the flood came and swept them all away; so will the coming of the Son of Man be [unexpected judgment].

But understand this: If the head of the house had known what time of the night the thief was coming, he would have been on the alert and would not have allowed his house to be broken into.