What heart actually means
Lev is the Hebrew word usually printed as "heart", and in Hebrew it is where a person thinks, weighs options, and decides. Solomon asks God for a listening lev so he can judge cases well. When the Hebrew Bible wants to locate an emotion in the body, it usually reaches for a different organ.
Where the word comes from
"The fool has said in his heart, 'There is no God.'" What Psalm 14:1 reports is a conclusion the man has reached, not a mood he is in. That is the ordinary force of lev and its longer form levav, which run to around 850 occurrences with the physical organ rarely in view. Proverbs 15:7 makes the same assumption: "The lips of the wise spread knowledge, but the hearts of fools are not dependable." What is unreliable there is their judgment.
In 1 Kings 3:9 Solomon asks for a lev shomea, a listening heart, so that he can tell good from bad in the disputes brought to him. Any English speaker asked to name the faculty he is requesting would say mind. The craftsmen who build the meeting tent in Exodus are called wise of heart, meaning they can plan a structure and execute it with their hands.
Feeling sits lower in the Hebrew body. Compassion is rachamim, from rechem, womb. Conscience and the deepest sensations are assigned to the kidneys, which is why Psalm 7:9 has God testing hearts and kidneys as a pair. Lev also means the middle of something with no person involved at all: the heart of the sea in Exodus 15:8, the heart of the heavens in Deuteronomy 4:11. It is the inside of a thing, where the working parts are.
Why "heart" gets in the way
English split the head from the heart and handed the feelings to the heart. That split is the default assumption a reader brings to the page, and it inverts particular verses. Proverbs 3:5 tells you to trust Yahweh with all your heart and not to lean on your own understanding, which in modern English sounds like an instruction to feel rather than think. In Hebrew both halves of that line concern thinking. The question is whose assessment you go with.
Proverbs 4:23 has taken the most damage. "Guard your heart" now circulates as advice about protecting yourself emotionally in relationships. The Hebrew calls the heart the source, using totsa'ot, the word for the outgoings or springs of a place. Everything a person says and does drains out from there, which makes the line an instruction about where conduct starts.
The same slippage hits the hardened heart. Pharaoh's lev is made heavy, or strong, or firm depending on the verb. In English that becomes emotional coldness, a man who has stopped feeling. The Hebrew describes a will that has set, a decision made and then held against the evidence.
What this translation prints instead
The NGET keeps "heart" on the page and lets the context do the rest. The reasoning the translator gives is that heart still communicates in modern English as the center of a person, while no single English word covers thinking, willing, and feeling at once. Swapping in mind everywhere would trade one partial rendering for another and would sound clinical in the poetry.
So Proverbs 21:1 reads "A king's heart is like a stream of water in Yahweh's hand," where the point is that his policy decisions get steered. Psalm 143:4 reads "My heart is numb with horror," where the Hebrew describes being stunned into paralysis. Both senses run through the English word without a footnote fighting the sentence.
Where the choice hides something, the concept notes carry it. A reader who wants to know that the fool's heart in Psalm 14 is his reasoning, or that Solomon asked for a mind that listens, can find that on the verse rather than having to already know Hebrew to notice the gap.
Read it in place
Then Hannah prayed: "My heart soars because of Yahweh; my strength is lifted high because of Yahweh. My mouth speaks boldly against my enemies, because I celebrate in your rescue."
1 Samuel 2:1
The king stood by the pillar and made a binding agreement before Yahweh -- to follow Yahweh and to keep his commands, his instructions, and his laws with all his heart and all his being, and to carry out the terms of this covenant written in this book. And all the people committed themselves to the agreement.
2 Kings 23:3
Joab son of Zeruiah could tell that the king's heart was longing for Absalom.
2 Samuel 14:1
A messenger came to David and reported, "The hearts of the people of Israel have shifted to Absalom."
2 Samuel 15:13
Questions people ask
What does heart mean in the Bible?
In the Hebrew scriptures heart translates lev, the inner center where a person thinks, plans, and decides. It covers emotion as well, but thought and will come first. Hebrew assigns tender feeling to the womb and the kidneys instead. So biblical statements about the heart are usually about judgment and intent rather than sentiment.
What does heart mean in Hebrew?
The word is lev, or levav in its longer form. It names the inside of anything: the middle of the sea, the middle of the sky, the middle of a person. Applied to a person it means the seat of reasoning and choice. Hebrew has no separate everyday word for the mind, so lev does that job too.
What does a hardened heart mean in the Bible?
The Hebrew phrases describe a lev that has become heavy, strong, or firm. Since lev is the seat of decision, a hardened heart is a will that has locked into position and stopped responding to evidence. Pharaoh is the main case. It describes stubbornness in the face of what he has seen, not an inability to feel.
What does a pure heart mean in the Bible?
It describes intentions with nothing mixed into them. Psalm 24:4 pairs clean hands with a pure lev, putting outward conduct next to the inward decisions that produced it. Because lev covers reasoning and will, a pure heart means a person whose motives are single, not a person whose feelings are especially warm.