'tat tvam asi'--jīva-hetu prādeśika vākya
praṇava nā māni' tāre kahe mahā-vākya
tat tvam asi—you are the same; jīva-hetu—for the enlightenment of the conditioned soul; prādeśika—subsidiary; vākya—vibration; praṇava—the oṁkāra incarnation; nā—not; māni'-accepting; tāre—that; kahe—says; mahā-vākya—transcendental vibration.
"The subsidiary vibration tat tvam asi ["you are the same"] is meant for the understanding of the living entity, but the principal vibration is oṁkāra. Not caring for oṁkāra, Śaṅkarācārya has stressed the vibration tat tvam asi."
Tat tvam asi is accepted as the primary vibration by one who does not accept praṇava, the transcendental sound incarnation of the holy name of the Lord, as the chief principle in Vedic literature. By word jugglery, Śaṅkarācārya tried to create an illusory presentation of the Supreme Personality of Godhead in His relationship with the living entities and the cosmic manifestation. Tat tvam asi is a warning to the living entity not to mistake the body for the self. Therefore tat tvam asi is especially meant for the conditioned soul. The chanting of oṁkāra or the Hare Kṛṣṇa mantra is meant for the liberated soul. Śrīla Rūpa Gosvāmī has said, ayi mukta-kulair upāsyamānam (Nāmāṣṭaka 1). Thus the holy name of the Lord is chanted by the liberated souls. Similarly, Parīkṣit Mahārāja says, nivṛtta-tarṣair upagīyamānāt (Bhāg. 10.1.4). The holy name of the Lord can be chanted by those who have fully satisfied their material desires or who are fully situated on the transcendental platform and devoid of material desire. The name of the Lord can be chanted by one who is completely freed from material contamination (anyābhilāṣitā-śūnyaṁ jñāna-karmādy-anāvṛtam). Śaṅkarācārya has indirectly minimized the value of the principal Vedic mantra (oṁkāra) by accepting a subordinate vibration (tat tvam asi) as the most important Vedic mantra.
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