'Heart' in the Bible

So the king said to me, “Why is your face sad though you are not sick? This is nothing but sadness of heart.” Then I was very much afraid.

Then my God put it into my heart to assemble the nobles, the officials and the people to be enrolled by genealogies. Then I found the book of the genealogy of those who came up first in which I found the following record:

“You found his heart faithful before You,And made a covenant with himTo give him the land of the Canaanite,Of the Hittite and the Amorite,Of the Perizzite, the Jebusite and the Girgashite—To give it to his descendants.And You have fulfilled Your promise,For You are righteous.