Allah indicates in the Qur’an those to whom He grants wisdom. According to what is related in the Qur’an, the main source of wisdom is the fear of Allah:
The starting point of fearing Allah is having a conception of the attributes of Allah and of the judgement Day. Allah grants man the sense to judge between right and wrong only when man fears Him. This is actually a kind of comprehension attained as a result of the softening heart with the fear of Allah:
Man should always strive to have more of this fear. To this end, he should pray, reflect on Allah’s power, might and punishment, and endeavour to have a deeper comprehension of Him.
So fear Allah as much as you can; listen and obey and spend in charity for the benefit of your own soul.Those saved from the covetousness of their own souls are the ones that achieve prosperity. (At-Taghabun, 16)
Possessing the sense to judge between right and wrong is an indication of the wisdom of a person. Such a person is surely endowed with the capacity to ponder. This gift of comprehension is called (insight) or “vision” in the Qur’an. Etymologically, in Arabic the origin of the word basirah “insight” is “to see.” Yet this is quite different from the normal act of seeing. A person lacking insight is described as one whose heart and mind is covered lest he should understand the Qur’an.”
And We cast a veil upon their hearts (and minds) lest they should understand the Qur’an, and made them hard of hearing. When you commemorate your Lord and Him alone in the Qur’an, they turn on their backs, fleeing (from the truth). (Al-Isra, 46)
The word “understand” in the verse above is of great significance. In many other verses, the lack of understanding prevalent among people is mentioned. This conveys a message: in the physical sense, unbelievers perceive ( in other words, they hear ) what they are told by believers, yet they fail to comprehend the meaning and content of the message. This is a state of inebriation, a shift of consciousness and a metaphysical fact. Allah informs us about a “veil cast over their hearts:”
And who is more wrong than one who is reminded of the signs of his Lord, but turns away from them, forgetting the (deeds) which his hands have sent forth? Truly, We have cast veils over their hearts lest they should understand this, and made them hard of hearing. if you called them to guidance, even then would they never accept guidance. (Al-Anfal, 57)
Unbelievers, every now and then, confess their inherent lack of understanding of the religion communicated to them. This is straightforwardly manifested in the verse where the people of Midian dare to say to Shu’aib, “O Shu’aib! much of what you say we do not understand! In fact, among us we see that you have no strength! Were it not for your family, we should certainly have stoned you! for you have among us no great position!”(Hud, 91)
No man devoid of understanding can be guided to the true path, except by the will of Allah. Allah states in the following verse:
Among them are some who (pretend to) listen to you: But can you make the deaf hear, incapable as they are of understanding? And among them are some who look at you : but can you guide the blind, bereft as they are of sight? (Jonah, 42-43)
Consequently, those who turn to faith are solely those who are endowed with wisdom and insight. Correspondingly, believers are under obligation to “call on Allah resting upon conscious insight:”
Say “This is my way: Resting upon conscious insight accessible to reason, I am calling (you alI) unto God—I and whosoever follows me.Glory to Allah! I am not of the idolaters. (Joseph, 108)
“Now have come to you, from your Lord, proofs (to open your eyes): if any will see, it will be for (the good of) his own soul; if any will be blind, it will be to his own (harm): I am not (here) to watch over your doings.” (Al-Anaam, 104)
Being deprived of insight and wisdom, unbelievers think it of benefit to themselves to avoid any struggle in the way of Allah. With such an attitude, they commit themselves to dwelling in Hell for all eternity:
Those who were left behind rejoiced in their inaction behind the back of the messenger of Allah: they had no wish to strive and fight, with their wealth and their persons, in the cause of Allah. they said, to each other, “Do not go forth to war in the heat.” Say, “The fire of Hell is fiercer in heat.” If only they could understand! (At-Tawba, 81)
When a Sura comes down, enjoining them to believe in Allah and to strive and fight along with His Messenger, those with wealth and influence among them ask you for exemption, and say: “Leave us (behind): we would rather be with those who sit (at home).” They prefer to be with (the women), who remain behind (at home): their hearts are sealed and so they do not understand. (At-Tawba, 86-87)