Valmiki Ramayana Aranya Kanda Sarga 5 Shloka 28
Original Shlokaमामेष वरदो राम ब्रह्मलोकं निनीषति। जितमुग्रेण तपसा दुष्प्रापमकृतात्मभिः।।3.5.28।।
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राम O Rama, एषः this god, उग्रेण severe, तपसा austerity, जितम् attained, अकृतात्मभिः by those who have not realised their self, दुष्प्रापम् most difficult, ब्रह्मलोकम the world of Brahman, माम् myself, निनीषति wishes to take me.
O Rama, Indra, the bestower of boons, wants to take me to the world of Brahma, earned by me through severe penance which is most difficult to be attained by those devoid of selfrealisation.