And when this serves as an admonition for one who has insight, and inclines him towards the Mighty, the Forgiving, it results in their denial of not taking heed. They counted their scriptures - in which they saw these towns in the manner that He, glorified and exalted is He, informed them of it - as nothing. So He, the Exalted, said: "Did they not travel in the land?" meaning while they are perceptive, looking with their eyes at what they pass by, of the visible signs from the destroyed towns and others. The encouragement to travel indicates sight.

And when the answer is established, it is known that it is negated because it is caused by the particle of denial, which means negation. It has entered upon the negation of traveling, thus negating it. Therefore, it affirmed the traveling devoid of what the answer indicated, which is His saying: "So that they may have hearts" that are aware, "by which they understand" what they see with their eyes in the visible signs indicating the Oneness of Allah, the Exalted, and His power over life and death whenever He wills, so that they may take heed by it. The absence of the described hearts is contingent upon the negation of the traveling, which is the affirmation of traveling. Similarly, the mention in the ears from His saying (or) meaning, or they may have, if they are blind of sight, as indicated by making this a counterpart to "ears by which they hear" the audible signs translated from those towns and others, whether they traveled or did not travel, if their insights are not penetrating in understanding by mere sight, so they contemplate it with their hearts. For the lack of sight does not harm them when there exists insight.

And when the harm to man is only the blindness of insight and not of sight, he negated blindness altogether from sight due to the lack of necessity with the illumination of insight. He specified it to sight because there is harm in it, even if sight is present as a cause of what has passed along with what he has guided to from the estimation. So he said: "For indeed, it is not the sight that is blind" meaning due to the lack of harm from its blindness, which is illuminated insight. "But the hearts are blind" and he emphasized the meaning by saying: "which are in the chests" due to the existence of harm from their blindness, which nullifies the benefit of its owner, even if sight is present. Thus, it was necessary in depicting their blindness to increase the specification of what is known, that blindness is indeed for sight, informing that the hearts did not mention it mistakenly, but rather intentionally, alerting that blindness of sight is a lack in comparison to their blindness. The intended meaning of the heart is a divine, spiritual essence deposited in the flesh of the pineal gland located on the left side of the chest, to which there is a connection... The minds of most believe that it resembles the connection of an attribute to the body, or a quality to the described, or a being to a place. And this essence, in the reality of man, is called a heart due to its proximity and connection. It is like a knight, and the entire body is like the horse. The blindness of the knight is more harmful to the knight than the blindness of the horse. In fact, there is no comparison of either harm to the other. Therefore, he negated the blindness of sight altogether and primarily, so there is nothing whose harm is in comparison to the blindness of insight.