yaj jñātvāmṛtam aśnute
anādi mat-paraṁ brahma
na sat tan nāsad ucyate
The Lord has explained the ﬁeld of activities and the knower of the ﬁeld. He has also explained the process of knowing the knower of the ﬁeld of activities. Now He begins to explain the knowable, ﬁrst the soul and then the Supersoul. By knowledge of the knower, both the soul and the Supersoul, one can relish the nectar of life. As explained in the Second Chapter, the living entity is eternal. This is also conﬁrmed here. There is no speciﬁc date at which the jīva was born. Nor can anyone trace out the history of the jīvātmā’s manifestation from the Supreme Lord. Therefore it is beginningless. The Vedic literature conﬁrms this: na jāyate mriyate vā vipaścit (Kaṭha Upaniṣad 1.2.18). The knower of the body is never born and never dies, and he is full of knowledge.
The Supreme Lord as the Supersoul is also stated in the Vedic literature (Śvetāśvatara Upaniṣad 6.16) to be pradhāna-kṣetrajña-patir guṇeśaḥ, the chief knower of the body and the master of the three modes of material nature. In the smṛti it is said, dāsa-bhūto harer eva nānyasvaiva kadācana. The living entities are eternally in the service of the Supreme Lord. This is also conﬁrmed by Lord Caitanya in His teachings. Therefore the description of Brahman mentioned in this verse is in relation to the individual soul, and when the word Brahman is applied to the living entity, it is to be understood that he is vijñāna-brahma as opposed to ānanda-brahma. Ānanda-brahma is the Supreme Brahman Personality of Godhead.