sloka padi' ache prabhu avista ha-iya
rupa-gosani asi' pade dandavat hana
sloka padi'-reading the verse; ache—remained; prabhu—the Lord; avista—in an ecstatic mood; ha-iya—being; rupa-gosani—Srila Rupa Gosvami; asi'-coming; pade—fell down; dandavat—like a rod; hana—becoming.
After reading the verse, Sri Caitanya Mahaprabhu went into a ecstatic mood. While He was in that state, Srila Rupa Gosvami came and immediately fell down on the floor like a rod.
The word danda means rod or pole. A rod or pole falls straight; similarly, when one offers obeisances to his superior with all eight angas (parts) of the body, he performs what is called dandavat. Sometimes we only speak of dandavats but actually do not fall down. In any case, dandavat means falling down like a rod before one's superior.
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