The corrupter of the heart is of two types:

One of them is that which corrupts it by itself like the forbidden which are two types:

● Forbidden relative to Allaah like carcasses, blood, pork, wild animals that kill with the canine tooth [6] and birds that kill with claws.

● Forbidden relative to Allaah’s slaves, like stolen, maghsoob, kidnapped, and what is taken without the permission of the owner either by force or by shame and blame.

The second is what corrupts as a result of its quantity and its exceeding limits, like wasting permissible things, excessive filling of the stomach, for it makes acts of obedience burdensome and it preoccupies the heart… chasing after belly desires and trying for it until it captures it. If it captures it he becomes preoccupied with following its activities and protecting the self from its harm, and being hurt by its weight, and it strengthens the elements of desire. It paves paths for Satan and expands them, for he moves among humans in the veins. Fasting narrows its passages and closes his paths and filling the stomach paves paths and widens them. Whoever eats a lot, drinks a lot, sleeps a lot and loses a lot. In the famous hadeeth:

“No human fills a container worse than his stomach. Two small portions of food to straighten his backbone are sufficient. If he must [eat more], then let it be a third for food, a third for drink and a third for breathing.”

It is said that [on one occasion] Iblees – may Allaah curse him – met Yahyaa, son of Zakariyyaa – peace be upon them – and Yahyaa asked him:

“Did you take anything from me.”
He replied:
“No, except one night when food was presented to you, I made it so desirable to you that you ate your fill and you went sleep without making your regular supplications.”

Yahyaa said:
“I swear by Allaah that I will never eat my fill again.”

Iblees then said:
“As for me, I swear by Allaah that I will never advise another human again.”