One has to ask, “How is the word 'heart' used in the Bible?” Perhaps I can propose the following in order to distinguish the definitions for the word heart:
(lēb), לֵבָב (lēbāb). Heart, understanding, mind (also used in idioms such as “to set the heart upon” meaning “to think about” or “to want”).
Concrete meanings of lēb referred to the internal organ and to analogous physical locations. However, in its abstract meanings, “heart” became the richest biblical term for the totality of man’s inner or immaterial nature. In biblical literature it is the most frequently used term for man’s immaterial personality functions as well as the most inclusive term for them since, in the Bible, virtually every immaterial function of man is attributed to the “heart.”[1]There are several things to consider here: (1) "heart" is used to describe an internal organ, and (2) "heart" is also used to describe something that lies within man. It also must be noted that inner nature of man is categorized as immaterial. Furthermore, the heart appears to cover every immaterial function from the nature of man.[2] Thus, the "heart" is the center of the internal nature of man (Exodus 36:2; Deuteronomy 28:47; Jeremiah 4:14; 4:19; Proverbs 10:20; 14:30; 1 Kings 3:12; 4:29; 8:17). However, I would also like to recognize the word "heart often refers to the mental faculties,"[3] which is important to establish, because it shows the heart is used interchangeably, metaphorically, and allegorically with the mind. Which begs the question: in what way is the heart different from the mind and soul of man?
cont.
[1] R. Laird Harris, Robert Laird Harris, Gleason Leonard Archer and Bruce K. Waltke, Theological Wordbook of the Old Testament, electronic ed. (Chicago: Moody Press, 1999). 466.
[2] There are different conceptions of what the nature of man really is. Some Christians hold to a tripartite nature of man, and others support a dualistic nature of man, and finally there are those who maintain a materialistic nature of man.
[3] NET Notes.
