for that constitutes the very food that feeds its sickness. Yet if wisdom and admonition reach it, they become among the foremost causes of its rectification and cure. The Exalted says (al-Ḥajj 22:53), “so that He may make what Satan casts a trial for those in whose hearts is a sickness and those whose hearts are hardened.” The former group are weak because of their illness, so whatever Satan casts turns into a temptation for them; the latter have hearts that are dry and unresponsive to faith, and the same thing becomes a temptation for them as well.

He likewise says (al-Aḥzāb 33:60), “If the hypocrites, those in whose hearts is a sickness, and the rumor-mongers in Medina do not desist…,” and He says (al-Muddaththir 74:31), “so that those in whose hearts is a sickness may say….” Their hearts have neither died like the hearts of the outright disbelievers and hypocrites, nor are they sound and wholesome like the hearts of the believers; instead, they are afflicted by the diseases of doubt and lust.

Again, in al-Aḥzāb (33:32) He says, “Do not be soft in speech, lest he in whose heart is a sickness should yearn.” This is the sickness of lust: if a woman were to present herself to a sound heart, it would pay her no heed, whereas a heart diseased by desire, owing to its weakness, inclines toward whatever of that sort comes before it, in proportion to the strength or weakness of the malady. Thus, when the women speak in a soft and alluring manner, the one whose heart is diseased begins to yearn.

The Quran is a healing for what lies within the breasts. For the one whose heart is afflicted by the diseases of doubts and desires, it contains clear proofs that separate truth from falsehood, removing the maladies of doubt that corrupt knowledge, perception, and understanding, so that he sees things as they truly are. It also offers wisdom and beautiful admonition—promises and threats, narratives rich with lessons—that bring about the heart’s rectitude, making it yearn for what benefits it and recoil from what harms it. Consequently, the heart comes to love guidance and hate misguidance after previously desiring misguidance and despising guidance.

Thus the Quran eliminates the diseases that generate corrupt wills until the heart is set aright, its intention corrected, and it returns to the innate disposition upon which it was created, just as the body returns to its natural state. The heart is nourished by faith and by the Quran, which purify and strengthen it, just as the body is nourished by whatever causes it to grow and stand upright. Indeed, the zakāh (purification) of the heart is like the growth of the body. In Arabic, zakāh means growth and increase in goodness; one says, “A thing zakā when it grew in righteousness.” The heart, therefore, needs to be reared so that it grows and increases until it is complete and sound, just as the body must be reared with foods that are beneficial to it.

Alongside that, one must also prevent whatever harms it: the body grows only when it is supplied with what benefits it and shielded from what harms it, and the heart will not become pure, grow, and attain full rectitude except by acquiring what benefits it and repelling what harms it. The same holds true for crops: they thrive only under these conditions.

Because charity extinguishes sin just as water extinguishes fire, the heart is purified and caused to grow through it; and its zakāh is something over and above mere cleansing from sin. Allah, Most High, says in al-Tawbah (9:103), “Take…”