In the name of Allah, the Compassionate, the Merciful.

All praise is due to Allah. We seek His help and His forgiveness, and we seek refuge with Allah from the evil within ourselves and from the consequence of our deeds. Whomever Allah guides, none can mislead; and whomever He allows to stray, none can guide. I testify that there is no deity worthy of worship but Allah alone, without partner, and I testify that Muhammad is His servant and His messenger. May Allah bless him, his family, and his Companions, and grant them perfect peace.

Section: The diseases of the heart and their cure

Allah the Exalted has said about the hypocrites: “In their hearts is a sickness, so Allah has increased their sickness” (al-Baqarah 2:10). He has also said: “So that He may make what Satan casts a trial for those whose hearts are diseased and whose hearts are hardened” (al-Hajj 22:53). And He said: “If the hypocrites, those in whose hearts is a sickness, and the alarm-mongers in Madinah do not desist, We shall certainly set you against them; then they will not remain your neighbors there except for a short while” (al-Ahzab 33:60). He likewise said: “…so that those who were given the Scripture and the believers might not doubt, and that those in whose hearts is a sickness and the disbelievers might say, ‘What did Allah intend by this parable?’ ” (al-Muddaththir 74:31). And He, the Most High, said: “There has come to you an exhortation from your Lord—a healing for what lies within the breasts, and a guidance and a mercy for the believers” (Yunus 10:57). He also said: “We send down from the Qur’an that which is a healing and a mercy for the believers, while it increases the wrongdoers only in loss” (al-Isra’ 17:82). And He said: “…and He will heal the breasts of a believing people and remove the rage from their hearts” (al-Tawbah 9:14–15).

The body’s illness is an interruption of its health and soundness—an inner corruption that spoils its perception and its natural movements. Its perception may be lost altogether, as in blindness or deafness, or it may perceive things contrary to their reality: tasting something sweet as bitter, or imagining things that have no existence outside the mind. Likewise, the corruption of its natural movements may appear when the digestive power becomes too weak, or when the body loathes the foods it needs while craving things that harm it, resulting in pain and distress.