The heart which remembers Allah Most High is protected
It is mentioned in Hadith that Satan places its snout on the heart and casts its whispers into it. When the heart engages in worship of Almighty Allah, Satan draws away.
This shows that Satan cannot dominate the heart which is engaged in remembrance of Almighty Allah. This is the reason the saints are safe from sins and the Prophets are inherently innocent, as their hearts are forever engaged in the remembrance of Allah Most High. Even while performing worldly tasks, they don’t become heedless.
The Holy Prophet Mohammed (صلى الله عليه وسلم ) says: People! Be apprehensive and save yourselves from Satan, because he tests you as to who among you is good in deeds. The intent here is that Almighty Allah says in the Holy Quran:
You will not any hold over My special servants.
When Satan gets no chance to cast whispers or stray thoughts or they are of no use, it understands that this person is among those whom I have no hold on.
It is difficult for every person to be of this status. We are such that the moment Satan casts a whisper, we start following it and our Selves strive to fulfill that wish. If there is nothing stopping us, then we will go ahead and fulfill that wish as well. The way a lunatic gets into his head to hit someone and immediately does it. Contrary to them, when the intelligent folk feel like hitting someone, they think over it. The greater the intelligence, the deeper this reflection. A very intelligent person will be the one who thinks as to why he got this thought and what the use of it is and what will happen if they do act on this.
Thus, the intelligent folk think as to who caused this thought. When they learn through their faith that could have been none other than Almighty Allah, they start thinking of the outcome of that thought – if they do what they feel like doing, will it please Almighty Allah or displease Him? If they get to know that it will please Him, they go ahead and do it and they will consider this thought as good in light of the following Hadith:
The Holy Prophet Mohammed (صلى الله عليه وسلم ) says: Allahumma A’amir Qalbee Min Wasaawisi Dhikrika Watrud ‘Annee Waswaasish Shaitaan.
Translation: O Allah! Fill My heart with Your remembrance and dispel from Me the whispers of Satan.
If they learn that that acting out that though would result in Almighty Allah being displeased, the fear of Almighty Allah Most High would envelop them and they understand that the attribute of misguidance and the means of it is Satan, as guidance and misguidance are both the works of Allah Most High.
[Excerpted from Maqasid Ul Islam, Vol. 8]