brahmarṣi-sevitān deśān
hitvaite 'brahma-varcasam
samudraḿ durgam āśritya
bādhante dasyavaḥ prajāḥ
brahma-rishi -- by great brahmana sages; sevitan -- graced; desan -- lands (like Mathura); hitva -- abandoning; ete -- these (Yadavas); abrahma-varcasam -- where brahminical principles are not observed; samudram -- the ocean; durgam -- a fortress; asritya -- taking shelter of; badhante -- they cause trouble; dasyavah -- thieves; prajah -- to their subjects.
These Yadavas have abandoned the holy lands inhabited by saintly sages and have instead taken shelter of a fortress in the sea, a place where no brahminical principles are observed. There, just like thieves, they harass their subjects.
The words brahmarshi-sevitan desan ("holy lands inhabited by saintly sages") allude to the district of Mathura. Srila Prabhupada writes, "Sisupala went crazy because of Krishna's being elected the supreme, first worshiped person in that meeting, and he spoke so irresponsibly that it appeared that he had lost all his good fortune."
