'Heart' in the Bible

The king said to me, "Why is your face sad, since you are not sick? This is nothing else but sorrow of heart." Then I was very much afraid.

I arose in the night, I and some few men with me; neither told I any man what my God put into my heart to do for Jerusalem; neither was there any animal with me, except the animal that I rode on.

Then I sent to him, saying, "There are no such things done as you say, but you imagine them out of your own heart."

My God put into my heart to gather together the nobles, and the rulers, and the people, that they might be reckoned by genealogy. I found the book of the genealogy of those who came up at the first, and I found written therein:

and found his heart faithful before you, and made a covenant with him to give the land of the Canaanite, the Hittite, the Amorite, and the Perizzite, and the Jebusite, and the Girgashite, to give it to his seed, and have performed your words; for you are righteous.