although it may also experience the kind of pain that physical illness causes in the rest of the body—that, however, is a separate matter. Thus, the heart’s illness and its healing are of greater consequence than bodily illness and its healing. At times, its illness consists of doubts.
As He says:
“so that one in whose heart is disease is moved to desire.”
Likewise, al-Kharā’itī composed The Book of Hearts Afflicted by Passions. The hearts of the hypocrites suffer illness in both respects: corruption of beliefs and corruption of desires.
The person who has been wronged also has an illness in his heart: the pain caused by another’s injustice toward him. When he receives his due in full, his heart is healed, as Allah Most High says:
“and heal the hearts of a believing people”
“and remove the anger from their hearts.”
The heart’s anger serves to repel harm and pain. Once the harm has been repelled and the person has received his due in full, his anger subsides.
When a person can no longer hear with his ears, see with his eyes, or speak with his tongue, this is a painful illness that deprives him of benefits and exposes him to harm. Likewise, when he cannot hear or see with his heart, distinguish truth from falsehood, or discern good from evil and error from right guidance, this is among the gravest illnesses and pains of his heart.
Similarly, when he craves something harmful, such as excessive food through an all-consuming appetite, or eating clay and the like, this is an illness. He suffers until his pain is relieved