PURPORT

There is a class of men akin to Mayavadi philosophers who misinterpret the aham brahmasmi and so'ham Vedic mantras to mean, "I am the Supreme Brahman" and "I am identical with the Lord." This kind of false conception, in which one thinks himself the supreme enjoyer, is a kind of illusion. It is described elsewhere in Srimad-Bhagavatam (5.5.8): janasya moho 'yam aham mameti. As explained in the above verse, Lord Saṅkarsana is the predominating Deity of this false conception. Krsna confirms this in Bhagavad-gita (15.15):

sarvasya caham hrdi sannivisto
mattah smrtir jnanam apohanam ca

"I am seated in everyone's heart, and from Me come remembrance, knowledge and forgetfulness." The Lord is situated in everyone's heart as Saṅkarsana, and when a demon thinks himself one with the Supreme Lord, the Lord keeps him in that darkness. Although such a demoniac living entity is only an insignificant part of the Supreme Lord, he forgets his true position and thinks he is the Supreme Lord. Because this forgetfulness is created by Saṅkarsana, He is sometimes called tamasi. The name tamasi does not indicate that He has a material body. He is always transcendental, but because He is the Supersoul of Lord Siva, who must perform tamasic activities, Saṅkarsana is sometimes called tamasi.

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