Valmiki Ramayana 6.111.21
गतासुर्भीमवेगस्तु नैर्ऋतेन्द्रो महाद्युतिः ।पपात स्यन्दनाद्भूमौ वृत्रो वज्रहतो यथा॥
gatāsurbhīmavegastu nairṛtendro mahādyutiḥ |papāta syandanādbhūmau vṛtro vajrahato yathā ||
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book