kali-yuge yuga-dharma--namera pracara
tathi lagi' pita-varna caitanyavatara
kali-yuge—in the Age of Kali; yuga-dharma—the religious practice for the age; namera—of the holy name; pracara—propagation; tathi—this; lagi'-for; pita-varna—having a yellow color; caitanya-avatara—the incarnation of Lord Caitanya.
The religious practice for the Age of Kali is to broadcast the glories of the holy name. Only for this purpose has the Lord, in a yellow color, descended as Lord Caitanya.
In this Age of Kali the practical system of religion for everyone is the chanting of the name of Godhead. This was introduced in this age by Lord Caitanya. Bhakti-yoga actually begins with the chanting of the holy name, as confirmed by Madhvacarya in his commentary on the Mundaka Upanisad. He quotes this verse from the Narayana-samhita:
dvapariyair janair visnuh
pancaratrais tu kevalaih
kalau tu nama-matrena
pujyate bhagavan harih
"In the Dvapara-yuga people should worship Lord Visnu only by the regulative principles of the Narada-pancaratra and other such authorized books. In the Age of Kali, however, people should simply chant the holy names of the Supreme Personality of Godhead." The Hare Krsna mantra is specifically mentioned in many Upanisads, such as the Kali-santarana Upanisad, where it is said:
hare krsna hare krsna
krsna krsna hare hare
hare rama hare rama
rama rama hare hare
iti sodasakam namnam
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