SB 1.3.33

yatreme sad-asad-rūpe
 pratiṣiddhe sva-saṁvidā
avidyayātmani kṛte
 iti tad brahma-darśanam
Synonyms: 
yatra — whenever; ime — in all these; sat-asat — gross and subtle; rūpe — in the forms of; pratiṣiddhe — on being nullified; sva-saṁvidā — by self-realization; avidyayā — by ignorance; ātmani — in the self; kṛte — having been imposed; iti — thus; tat — that is; brahma-darśanam — the process of seeing the Absolute.
Translation: 
Whenever a person experiences, by self-realization, that both the gross and subtle bodies have nothing to do with the pure self, at that time he sees himself as well as the Lord.
Purport: 

The difference between self-realization and material illusion is to know that the temporary or illusory impositions of material energy in the shape of gross and subtle bodies are superficial coverings of the self. The coverings take place due to ignorance. Such coverings are never effective in the person of the Personality of Godhead. Knowing this convincingly is called liberation, or seeing the Absolute. This means that perfect self-realization is made possible by adoption of godly or spiritual life. Self-realization means becoming indifferent to the needs of the gross and subtle bodies and becoming serious about the activities of the self. The impetus for activities is generated from the self, but such activities become illusory due to ignorance of the real position of the self. By ignorance, self-interest is calculated in terms of the gross and subtle bodies, and therefore a whole set of activities is spoiled, life after life. When, however, one meets the self by proper culture, the activities of the self begin. Therefore a man who is engaged in the activities of the self is called jīvan-mukta, or a liberated person even in the conditional existence.

This perfect stage of self-realization is attained not by artificial means, but under the lotus feet of the Lord, who is always transcendental. In the Bhagavad-gītā the Lord says that He is present in everyone’s heart, and from Him only all knowledge, remembrance or forgetfulness take place. When the living being desires to be an enjoyer of material energy (illusory phenomena), the Lord covers the living being in the mystery of forgetfulness, and thus the living being misinterprets the gross body and subtle mind to be his own self. And by culture of transcendental knowledge, when the living being prays to the Lord for deliverance from the clutches of forgetfulness, the Lord, by His causeless mercy, removes the living being’s illusory curtain, and thus he realizes his own self. He then engages himself in the service of the Lord in his eternal constitutional position, becoming liberated from the conditioned life. All this is executed by the Lord either through His external potency or directly by the internal potency.