tad-upasparsanad eva
japanto brahma paramam
tepus tatra mahat tapah
tat—of that holy place; upasparsanat—by bathing regularly in the water; eva—indeed; vinirdhuta—completely purified; mala-asayah—of all the dirt within the heart; japantah—chanting or murmuring; brahmamantras beginning with om (such as om tad visnoh paramam padam sada pasyanti surayah); paramam—the ultimate goal; tepuh—performed; tatra—there; mahat—great; tapah—penances.
At Narayana-saras, the second group of sons performed penances in the same way as the first. They bathed in the holy water, and by its touch all the dirty material desires in their hearts were cleansed away. They murmured mantras beginning with omkara and underwent a severe course of austerities.
Every Vedic mantra is called brahma because each mantra is preceded by the brahmaksara (aum or omkara). For example, om namo bhagavate vasudevaya. Lord Krsna says in Bhagavad-gita (7.8), pranavah sarva-vedesu: “In all the Vedic mantras, I am represented by pranava, or omkara.” Thus chanting of the Vedic mantras beginning with omkara is directly chanting of Krsna’s name. There is no difference. Whether one chants omkara or addresses the Lord as “Krsna,” the meaning is the same, but Sri Caitanya Mahaprabhu has recommended that in this age one chant the Hare Krsna mantra (harer nama eva kevalam [Adi 17.21]). Although there is no difference between Hare Krsna and the Vedic mantras beginning with omkara, Sri Caitanya Mahaprabhu, the leader of the spiritual movement for this age, has recommended that one chant Hare Krsna, Hare Krsna, Krsna Krsna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare.

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