Know that the life of the heart—and indeed of anything else—is not simply a matter of sensation and voluntary motion, nor is it merely knowledge and power, as a group of speculative theologians have imagined with respect to Allah’s knowledge and power, such as Abū l-Ḥusayn al-Baṣrī. They claimed that “life” means nothing more than the capacity to know and to act. In truth, life is an attribute that inheres in the being to whom it is ascribed. It is a prerequisite for knowledge, will, and the power to perform voluntary acts, and it also entails them. Every living being possesses perception, will, and voluntary action through power; conversely, any being that has knowledge, will, and voluntary action is alive.

The term ḥayāʾ (modesty) is derived from ḥayāh (life). When the heart is alive, its possessor enjoys a living sense of modesty that restrains him from disgraceful deeds, for the life of the heart is what bars the ugly acts that corrupt it. Hence the Prophet—peace and blessings be upon him—said, “Modesty is part of faith,” and, “Modesty and diffidence are two branches of faith, whereas foul speech and self-display are two branches of hypocrisy.” A living creature repels what harms it, unlike one that is dead and devoid of life. Such a dead-hearted person is described as waqiḥ, impertinent: waqāḥah is hardness, a dryness opposed to the moistness that signifies life. If someone is impertinent, dry, and stiff-faced, there is no life in his heart to generate modesty and keep him from ugliness, just as a parched earth is unaffected by the trampling of feet, unlike fresh green soil. The truly modest person, by contrast, shows palpable distress at what is shameful; he has a will that restrains him from committing it, unlike the impertinent one who feels no modesty and whose lack of faith offers him no deterrent.

When the heart is alive and a human being dies because his soul departs from his body, the death of the self is merely that separation; the soul itself is not dead in the sense of losing its own life. Thus Allah says in Sūrat al-Baqarah, “Do not say of those who are killed in the path of Allah, ‘They are dead’; rather, they are alive,” and in Sūrat Āl ʿImrān, “Never think of those who are killed in the path of Allah as dead; rather, they are alive.” Although such martyrs are included in the declaration of Āl ʿImrān, “Every soul shall taste death,” and in His words in Sūrat al-Zumar, “You will surely die, and they too will surely die,” and in Sūrat al-Ḥajj, “He is the One who gave you life, will then cause you to die, and will then give you life again,” the death that is affirmed is not the death that is negated. The affirmed death is the soul’s parting from the body; the negated death is the total extinction of life from both soul and body.

Sleep is likewise the twin of death. It is called wafāh (“taking”) and even “death,” yet life is still present in both sleeper and soul. Allah says in Sūrat al-Zumar, “Allah takes souls at the time of their death, and those that do not die in their sleep; He keeps those for whom He has decreed death and releases the others until an appointed term.” When the Prophet—peace and blessings be upon him—awoke from sleep he would say, “Praise be to Allah who revived us after He had caused us to die, and to Him is the resurrection,” and in another report, “Praise be to Allah who returned my soul to me, granted soundness to my body, and permitted me [to remember Him].”