The heart is like a fort and Satan the advancing enemy, who is intent on infiltrating and occupying it. Hence, only by guarding the gates, entrances and vulnerable positions, will it be impenetrable. Yet, a person who is unacquainted with the structure of the fortress, particularly its access points, cannot adequately defend it. By the same token, the obligation of guarding the heart from the whispers of Satan cannot be fulfilled and he cannot be warded off, unless a person knows the gates to the heart that Satan may take.

　　These gateways are, generally, personal characteristics, of which there are many, but, here, we will only refer to the ones that are so wide so as to accommodate all the numerous soldiers of Satan. These include:

　　- Satiating oneself: This is one of Satan's gateways to the heart; although lawful, eating in excess strengthens one's desires, which, in turn, are his weapons.

　　- Thinking ill of Muslims: Allah the Almighty Says (what means): {O you who have believed! Avoid much suspicion, indeed some suspicions are sins.} [Quran 49: 12]. Indeed, only hypocrites seek out flaws in others, whereas believers seek excuses for them.

　　A person may now ask: “How can one ward Satan off? Is it enough to be in constant remembrance of Allah the Almighty or to utter [phrases like] ‘La hawla wala quwwata illa billah (There is no power or strength except in Allah)’?” The answer is that you must know that the course of treatment to save one's heart from the whispers of Satan is to block the gateways [he takes] and to purify the heart from the aforementioned bad characteristics.

　　This needs to be further elaborated. The remembrance of Allah the Almighty should indeed suffice in stopping Satan from passing by or whispering in one’s heart. However, that cannot happen unless the heart itself is already of a pious nature and purified from evil characteristics. If not, words of His remembrance will be no more than mere thoughts without any impact on the heart or substance to deflect Satan. Allah the Almighty Says (what means): {Indeed, those who are pious - when an impulse touches them from Satan, they remember [Him] and at once they have insight.} [Quran 7: 201]. Therefore, since this is only confined to the pious, once a person manages to uproot evil traits from within, Satan may pass by or whisper, but will never be able to reside in the heart.

　　You see, Satan is like an approaching starved dog; if a person has neither bread nor meat, it will move away just by your voice which commands it to “go away”. However, if you have meat in your hands and the dog is hungry, it will attack the flesh and your mere words will not be enough to keep the animal at bay.

　　Similarly, if the heart is free from anything Satan can feed on, Thikr (remembrance of Allah The Almighty) will be enough to fend it off. On the other hand, if a person’s desires dominate his or her heart, the influence of Thikr is restricted to the outer edges of the heart and instead, its core becomes a residence for Satan. The Prophet, , said: "The heart is touched twice: [one of it is] a touch by the angel [which constitutes] a command of goodness and an acceptance of the truth. So, if a man experiences this, he should know that it is from Allah the Almighty and he should consequently thank Him. On the other hand, [there is] a touch from the enemy [Satan, and that constitutes an] insinuation of evil, disbelief in truth and being barred from good. So, if a person experiences this, he should seek refuge with Allah from the accursed Satan.” Then, the Prophet, , recited the Saying of Allah the Almighty (which means): {Satan threatens you with poverty and orders you to immorality.}.[Quran 2:268].”[An-Nasa’i and At-Tirmithi]

　　Expounding on this, Al-Hasan said: "They [i.e., the two touches] are actually two concerns that occur to the heart: one from Allah the Almighty and the other from the enemy [Satan]. May Allah have mercy upon a slave who examines his concerns and lets that affect him which is from Allah The Almighty, and strives against whatever he deems from the enemy.”

　　By nature, the heart equally accepts both the inspiration of an angel and the incitement of Satan, such that there is a balance. However, the latter aspect dominates when a person acts ravenously and indulges in desires, whereas the former overrules it if a person turns away from wants and whims, and resists them.

　　When man becomes subservient to his desires and his actions become driven by rage, the influence of Satan will prevail via whims, which are his haven, and the heart will become Satan’s nest and pasture. On the other hand, if a person strives against his or her desires, barring them from impacting him or her and adopts some angelic traits, his or her heart will become the dwelling and station of angels. Thus, the soldiers of angels and of Satan are in an epic struggle, until the heart opens to one of them, allowing them to reside within and dominate; the other party, then, will only be able to pass with stealth.

　　Unfortunately, most hearts are conquered by the soldiers of Satan, sustained by obedience to desires and whims, and, therefore, the organs are riddled with base notions that give preference to this temporary life, with clear disregard of the Hereafter. The heart cannot be recaptured except when it is purified from the nutrition of Satan and is supported with the remembrance of Allah the Almighty, which is the haven of angels.

　　Responses of the heart to temptation

　　Huthayfah ibn Al-Yaman narrated that the Prophet, , said:"Temptations are presented to hearts in the same way as a reed mat is woven, stick by stick. Any heart which is saturated by them will receive a black mark, whereas any heart that rejects them will have a white mark put on it. The result is that there will be two types of hearts: a black and dusty heart, which is like an uneven vessel that neither recognizes good nor rejects evil, except what is impregnated into it of desires; and a white heart that will never be harmed by any temptation, as long as there are heavens and the earth." [Muslim]

　　When the lure of desire and doubts are presented to the heart, it transforms into either of two types:

　　- The first is a heart that absorbs temptation in the same way a sponge soaks up water. This one will get a black stain every time it gives in to a temptation, until it becomes wholly dark and uneven. When this happens, the heart will be susceptible to two dangerous diseases: firstly, it will be unable to differentiate between good and evil, to the extent that it will not recognize either of them. Thereafter, the illness will pervade the organ until a person believes that good is evil and evil is good, the Prophetic Sunnah is a religious innovation and vice versa, and that truth is falsehood and the opposite holds true as well. Secondly, the heart will begin to be subservient to its whims, making them a criterion for judging the teachings of the Prophet, , sallam.

　　- The second is the white heart that is illuminated by the light of faith. When temptations are presented to it, it will immediately deny and reject them, thereby increasing in brightness and radiance.

　　As for the temptations themselves, they are categorized into two: desires and doubts. While the first leads to the corruption of both intentions and one’s will, the second taints a person’s knowledge and belief.

　　Accordingly, diseases of the heart are also of base desires and doubts; the former can be interpreted by the verse in which Allah the Almighty Says (what means): {Do not be soft in speech [to men], lest he in whose heart is disease should covet.} [Quran 33: 32] Unlike a healthy person, a patient is more sensitive to the slightest changes in heat, cold or movement; likewise, when the heart suffers from an illness, even a small amount of whims or doubts harms it and it is unable to ward them off. On the other hand, a sound heart powerfully fends off these temptations, even in the face of more attacks.

　　As for the other kind, Allah the Almighty referred to the disease of doubt, when He Said (what means): {In their hearts is disease, so Allah has increased their disease.} [Quran 2: 10] Commenting on this verse, Qatadah and Mujahid stated that “disease” here refers to misgivings.

　　Although illnesses of the heart come in these two forms, the Glorious Quran is a remedy for both. It includes decisive proofs that distinguish between truth and falsehood; with them, the disease of doubt, which corrupts a person’s knowledge and intellect, is removed, and a person can perceive things in their real form. Thus, the Quran is the true cure for malicious allegations and doubts. Yet, its effectiveness is contingent on understanding the Quran and comprehending its essence. And, if Allah the Almighty grants that to a person, his or her heart will as clearly distinguish between truth and falsehood, as it does between night and day.

　　Additionally, the Quran heals the other of the two diseases: desire; for, it includes wisdom, admonition and encouragement. It also contains verses warning people against indulging in the worldly life and instead urging them to work for the Hereafter. Furthermore, it has parables and stories that illustrate various lessons and warnings. Contemplating all this, a sound heart will surely incline towards what benefits it in both worlds and turn away from what will be of harm. The heart will then love guidance and detest vice.

　　Thus, the Glorious Quran removes diseases that result in corrupt yearnings; it reforms the heart, and so, reforms its wants, thus restoring it to the natural, pure state that it was created in. Referring to this, Allah the Almighty Says (what means):

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