How can one strengthen the faith of someone whose understanding of certain verses of the Holy Quran is questioned by Satan, such as the verse: "O people, a parable is presented, so listen to it. Indeed, those you invoke besides Allah will never create [as much as] a fly, even if they gathered together for it. And if a fly should steal anything from them, they would not be able to recover it from him. Weak are the pursuer and pursued"?

Whispers (waswas) are an affliction and a ploy from Satan. Their cure lies in resisting them and not paying them any attention. The Prophet, peace and blessings be upon him, praised Allah Almighty who reduced Satan's cunning to mere whispers. Rejecting these whispers is a sign of goodness, and ignoring them causes no harm.

The most beneficial cure for whispers is to turn towards the remembrance of Allah Almighty and to be pleased with the whispers for cutting off Satan, as a thief does not target a ruined house.

Their cure also lies in completely disregarding them, which is sufficient. For whoever does not pay attention to them, they will disappear. But whoever listens to them will find them increasing until they drive him to madness. Whispers are from Satan, who wishes to lead the believer astray.

One must differentiate between doubt (shakk) and whispers. Whispers are what assail the heart without choice, and hating them is a clear sign of faith. The way to strengthen one's faith is by knowing the Most Beautiful Names of Allah and His Exalted Attributes and supplicating with them, and by studying the books of the people of knowledge concerning this.