'Heart' in the Bible

I wrote to you out of great sorrow and anguish of heart along with many tears not to make you sad but to let you know how much love I have for you.

But thanks be to God, who placed in the heart of Titus the same dedication to you that I have.

Each of you must give what you have decided in your heart, not with regret or under compulsion, since God loves a cheerful giver.