Imam Khomeini explains the matter in his famous book of "an exposition on Forty Hadith" explains the matter as following:
This grade itself consists of different stages (fusul). You have to know that the lowest of them is the worldly and outward human existence comprising the initial stages of the self and its apparent manifestations.
The divine spark is blended with the physical to form man’s earthly existence. It is here in this body that the armies of good and evil are stationed, and the visible potentialities of body function as warring forces. It has seven quarters.
They are ears, eyes, tongue, stomach, private parts, and arms and legs.
All these diffused faculties under the control of the self are employed by the self in seven spheres of life. The seat of imagination also is an important faculty, as the thought and imagination are sovereign over all visible and invisible human faculties.
Thus the jihad of the self is the jihad of greater importance. m under the yoke of God’s command, and purging the domain of our body of satanic elements and their forces.This jihad is superior to being killed in the way of God, since this condition implies overpowering one’s own powers and faculties, and placing the