Explanation of the words of Imam al-Nawawi (may Allah have mercy on him) regarding what he quoted: "

The Shaykh : In the name of Allah, the Most Gracious, the Most Merciful:
The author (may Allah have mercy on him) said regarding the remaining verses he cited in the chapter on being mindful of Allah the Mighty and Majestic. He, the Exalted, says about Himself: . "He knows" means Allah the Mighty and Majestic knows the treachery of the eyes, that is, their betrayal. Here, "treachery" (khaynah) is a verbal noun, like "consequence" (aqibah) and "safety" (afiyah) and the like. It is also permissible to treat it as an active participle, derived from the verb "to betray" (khana), in which case it would be an example of adding a description to the thing described.
In any case, this is a grammatical issue that does not matter. The important point is that the eyes have treachery; the eyes possess a form of betrayal. This is because a person looks at something, and you might not think he is looking at it in a forbidden way, but Allah the Mighty and Majestic knows that he is looking at it in a forbidden way. Similarly, he looks at a person with a look of hatred, and the person being looked at does not know that this is a look of hatred, but Allah the Exalted knows that he is looking with a look of hatred. Likewise, a person looks at something forbidden, and the person who sees this viewer does not know whether he is looking at this thing with a look of disapproval or a look of approval, but Allah, Glorified and Exalted is He, is the One who knows that. So He, Glorified and Exalted is He, knows the treachery of the eyes, and He also knows what the breasts conceal, meaning the hearts, because the hearts are in the breasts. The hearts are the seat of intellect, understanding, and deliberation, or the means by which deliberation occurs, as Allah, Blessed and Exalted is He, said: . Glory be to Allah! It is as if this verse was revealed regarding the state of people today, or rather, the state of people from long ago. I mean, is the intellect in the brain or in the heart?
This is a matter that has confused many of those who look at things with a materialistic perspective and do not refer to the saying of Allah and the saying of His Messenger (peace and blessings be upon him). Otherwise, the truth is that the matter is clear: the intellect is in the heart, and the heart is in the chest: "with these hearts," . He did not say "the hearts that are in the brains"; He said: . So the matter is very clear that the intellect is in the heart. This is supported by the saying of the Prophet (peace and blessings be upon him): . So what can be said about a matter attested to by the Book of Allah, and Allah the Exalted is the Creator who knows everything, and attested to by the Sunnah of the Messenger (peace and blessings be upon him)!
It is obligatory for us, in light of this, to discard every statement that contradicts the Book of Allah and the Sunnah of His Messenger (peace and blessings be upon him), and to place it under our feet, and not to raise our heads with it. So the heart is the seat of the intellect, without a doubt. However, the brain is the seat of conception. The seat of conception visualizes things, and once it has visualized and prepared them, it sends them to the heart. Then the heart commands or forbids. It is as if, according to what we know, the brain is a secretary who prepares things and then hands them over to the heart. Then the heart directs, commanding or forbidding. This is not strange: . In this body, there are strange things that baffle the intellects. It is not strange that Allah, Glorified and Exalted is He, places conception in the head, so the brain visualizes and organizes things until only the commands remain, and then it sends them to the heart. Then the heart moves, commanding or forbidding. This is because the Prophet (peace and blessings be upon him) said: . If the command did not belong to the heart, it would not be the case that: . So the hearts are the seat of the intellect and deliberation for a person, but there is no doubt that they are connected to the brain. For this reason, if the brain is disrupted, thinking is corrupted and the intellect is corrupted. So this is connected to that, but the deliberating intellect is in the heart, and the heart is in the chest: .