Valmiki Ramayana Kishkindha Kanda Sarga 11 Shloka 75
Original Shlokaदृश्यन्ते चास्य कर्माणि दुष्कराणि सुरैरपि। यानि सञ्चिन्त्य भीतोऽहमृश्यमूकं समाश्रितः4.11.75।।
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सुरैरपि even by gods, दुष्कराणि difficult, तस्य his, कर्माणि tasks, दृश्यन्ते are seen(all over), यानि all those, सञ्चिन्त्य thinking of, भीतः fear, अहम् I, ऋष्यमूकम् at Rishyamuka, उपाश्रितः I have taken refuge.
'Even gods cannot do what he has done. Thinking of all this and being afraid of him, I have taken refuge at Rishyamuka.