Valmiki Ramayana Bala Kanda Sarga 16 Shloka 4
Original Shlokaस हि तेपे तपस्तीव्रं दीर्घकालमरिन्दम । येन तुष्टोऽभवद्ब्रह्मा लोककृल्लोकपूर्वज:।।1.16.4।।
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अरिन्दम ODestroyer of foes, स: Ravana, दीर्घकालम् for long time, तीव्रम् severe, तप: penance, तेपे performed, येन by which, लोककृत् creator of the world, लोकपूर्वज: born prior to the creation of the worlds, ब्रह्मा Brahma, तुष्ट:अभवत् was very pleased.
"O destroyer of foes Lord Brahma was very pleased with Ravana's intense penance over a long time৷৷