15.15 सर्वस्य of all, च and, अहम् I, हृदि in the heart, सन्निविष्टः seated, मत्तः from Me, स्मृतिः memory, ज्ञानम् knowledge, अपोहनम् (their) absence, च and, वेदैः by the Vedas, च and, सर्वैः (by) all, अहम् I, एव even, वेद्यः to be known, वेदान्तकृत् the author of the Vedanta, वेदवित् the knower of Vedas, एव even, च and, अहम् I.Commentary: I am seated in the hearts of all sentient beings as their innermost Self. Therefore from Me, the Self of all beings, are memory, knowledge and their loss. Righteous persons have knowledge and memory as a result of virtuous deeds. Sinful persons have loss of memory and knowledge as a result of vicious deeds. Virtue promotes peace and hence intellectual powers.Apohanam Loss (destruction or absence) of memory and knowledge, as also of the reasoning faculty. The loss of memory and knowledge is due to lust, anger, grief and delusion.Smriti Memory. It is a special modification of the mind (Antahkarana Vritti) born of the Samskaras that causes the revival of the past experiences or enjoyments of sensual objects of this life in a worldy man who has not practised Yoga. A Yogi gets revival of experiences of his past lives and transcendental knowledge that is beyond time, space and causation and visible nature.I am the central topic of the Vedas. To understand the Vedas is to Know Me. I, the Supreme Being, am to be known in all the Vedas. It is I Who know the Vedic teaching or the meaning of the Vedas. I cause the teaching of the Vedanta to be handed down in regular succession. I am the author of what is beyond the Vedas, viz., the Upanishads that constitute the Vedanta, that deal with the transcendental Supreme Being beyond all names and forms and devoid of all alities.A brief description of the glories of the Lord Narayana as manifested through special vehicles has been given in the above four verses. From the next verse a description of the form of Purushottama Who is free from any limiting adjunct is given. (Cf.X.20)