Valmiki Ramayana Sundara Kanda Sarga 55 Shloka 30
Original Shlokaअहो खलु कृतं कर्म दुष्करं हि हनूमता। अग्निं विसृजताऽभीक्ष्णं भीमं राक्षसवेश्मनि।।5.55.30।।
1 source checked for this shloka
राक्षसवेश्मनि in the demons buildings, आभीक्ष्णम् excessively, भीमम् terrific, अग्निम् fire, विसृजता spreading, हनूमता by Hanuman, दुष्करम् marvellous, कर्म task, कृतं खलु has been done verily, अहो Oh
'Oh Hanuman has indeed accomplished the marvellous task of spreading the terrific fire on the demons buildings.