Valmiki Ramayana Yuddha Kanda Sarga 110 Shloka 30

रावणस्य Ravana's, जीवितक्षये life not ceased, अन्तः end, न चैवदृश्यते not able to see, ततः then, सर्वास्त्रवित् knower of all knowledge, वीरः valiant, कौसल्यानन्दवर्धनः enhancer of Kausalya's joy, बहुभिः many, मार्गणैः ways, युक्तः well versed, राघवःRaghava, चिन्तयामास started thinking

Rama, knower of all shastras, valiant, enhancer of Kausalya's joy, well versed in the use of weapons, was not able to see the end of Ravana's life. He started thinking.