issues the properties of foods to the rest of the veins, limbs, and joints; then the bodies attain well-being and sound strength in proportion to the benefit of those properties and the readiness of the veins to receive them—provided the food is pure and the health is good; otherwise, it is not. For if the food is mixed with lethal poisons, the bodies will suffer harm from it in proportion to the strength or weakness of the poisons. Likewise is the case regarding the heart, which is the pool of sciences; for the knowledge that descends into the heart must issue its meanings—which are symbolized by the properties of foods—to the Spirit and the Intellect. Thus, they both attain from its meanings an increase in faith and obedience to Allah the Almighty, in proportion to the strength of knowledge and the strength of the readiness to receive it, just as the body attains an increase in well-being and strength from the properties of the food that the stomach issues, in proportion to strength and weakness. Likewise is the case regarding the corrupt Outward Knowledge (Al-'Ilm al-Zahir al-Fasid) that descends into the heart; the Spirit and the Intellect suffer corruption and destruction from it in proportion to its strength and the strength of its acceptance, just as the body suffers destruction and harm from the lethal poison that descends into the stomach of its eater, in proportion to its strength and its acceptance—measure for measure (waznan bi-wazn); and Allah knows best.

Among the sayings indicating the censure of the People of the Outward (Ahl al-Zahir) and their knowledge, and the censure of