Imam Ibn Al-Qayyim said:
The enemy of ALLAH, the devil, knew that the heart held the central position on which everything depended; so, he endeavoured to fill it with all sorts of whispers and vain desires with the intention of diverting it from the right path. He surrounded it with sources of misguidance and set devices and nets to trap it. To get out of his tricks is not possible except by seeking the help of ALLAH, sticking to the causes of His pleasure and acquiring the humility of servitude, which is the best weapon a man can have to enjoy the protection of ALLAH.
He said to Satan:
You will have no power over My servants (15:42) Since ALLAH Almighty by His grace gave me knowledge of the diseases of the hearts and their cure, and the whisperings of Satan in them, which result in affecting them and consequently spoiling the works of man, I decided to record the information in this book.