Valmiki Ramayana 5.2.26
तस्याश्च महतीं गुप्तिं सागरं च निरीक्ष्य सः ।रावणं च रिपुं घोरं चिन्तयामास वानरः॥
tasyāśca mahatīṃ guptiṃ sāgaraṃ ca nirīkṣya saḥ |rāvaṇaṃ ca ripuṃ ghoraṃ cintayāmāsa vānaraḥ ||
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book