Srimad Bhagavatam Canto 11, Chapter 28, Text 11

SB 11.28.11

atmavyayo ’gunah suddhah
 svayam-jyotir anavrtah
agni-vad daru-vad acid
 dehah kasyeha samsrtih
 
Translation: 
 
The spirit soul is inexhaustible, transcendental, pure, self-luminous and never covered by anything material. It is like fire. But the nonliving material body, like firewood, is dull and unaware. So in this world, who is it that actually undergoes the experience of material life?
 
Purport: 
 
The words anavrtah and agni-vat are significant here. Fire can never be covered with darkness because by nature fire is illuminating. Similarly, the spirit soul is svayam-jyotih, or self-luminous, and thus the soul is transcendental — he can never be covered by the darkness of material life. On the other hand, the material body, like firewood, is by nature dull and unilluminated. In itself it does not have any awareness of life. If the soul is transcendental to material life and the body is not even conscious of it, the following question arises: How does our experience of material existence actually take place?
Srimad Bhagavatam Canto 11, Chapter 28, Text 10
Srimad Bhagavatam Canto 11, Chapter 28, Text 12