'Heart' in the Bible

So the king said to me, "Why do you appear to be depressed when you aren't sick? What can this be other than sadness of heart?" This made me very fearful.

I got up during the night, along with a few men who were with me. But I did not tell anyone what my God was putting on my heart to do for Jerusalem. There were no animals with me, except for the one I was riding.

My God placed it on my heart to gather the leaders, the officials, and the ordinary people so they could be enrolled on the basis of genealogy. I found the genealogical records of those who had formerly returned. Here is what I found written in that record:

When you perceived that his heart was faithful toward you, you established a covenant with him to give his descendants the land of the Canaanites, the Hittites, the Amorites, the Perizzites, the Jebusites, and the Girgashites. You have fulfilled your promise, for you are righteous.