PURPORT

Srila Bhaktivinoda Thakura informs us that this letter from Rupa Gosvami to Sanatana Gosvami is mentioned by the annotator of Udbhata-candrika. Srila Rupa Gosvami wrote a note to Sanatana Gosvami from Bakla. This note indicated that Sri Caitanya Mahaprabhu was coming to Mathura, and it stated:

yadu-pateh kva gata mathura-puri
raghu-pateh kva gatottara-kosala
iti vicintya kurusva manah sthiram
na sad idam jagad ity avadharaya

"Where has the Mathura Puri of Yadupati gone? Where has the northern Kosala of Raghupati gone? By reflection, make the mind steady, thinking, 'This universe is not eternal.' "