kintu krsnera yei haya avatara-kala
bhara-harana-kala tate ha-ila misala
kintu—but; krsnera—of Lord Krsna; yei—that which; haya—is; avatara—of incarnation; kala—the time; bhara-harana—of taking away the burden; kala—the time; tate—in that; ha-ila—there was; misala—mixture.
But the time to lift the burden of the world mixed with the time for Lord Krsna's incarnation.
We have information from the Bhagavad-gita that the Lord appears at particular intervals to adjust a time-worn spiritual culture. Lord Sri Krsna appeared at the end of Dvapara-yuga to regenerate the spiritual culture of human society and also to manifest His transcendental pastimes. Visnu is the authorized Lord who maintains the created cosmos, and He is also the principal Deity who makes adjustments for improper administration in the cosmic creation. Sri Krsna is the primeval Lord, and He appears not to make such administrative adjustments but only to exhibit His transcendental pastimes and thus attract the fallen souls back home, back to Godhead.
However, the time for administrative rectification and the time for Lord Sri Krsna's appearance coincided at the end of the last Dvapara-yuga. Therefore when Sri Krsna appeared, Visnu, the Lord of maintenance, also merged in Him because all the plenary portions and parts of the absolute Personality of Godhead merge in Him during His appearance.
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