Ramayana
भूयो बन्धाद्विमुक्तेन भाषयित्वा दशाननम् । लङ्का भस्मीकृता येन पावकेनेव मेदिनी ॥ 7-35-7 ॥
It was by him, set free again from his bondage and having spoken his words to Ravana, that Lanka was reduced to ashes, just as the earth is consumed by fire.
english translation