Valmiki Ramayana Yuddha Kanda Sarga 69 Shloka 66

ततः then, नरान्तकः Naranthaka, मारुततुल्यवेगम् at wind speed, हयम् horse, आरुह्य mounting on top, निशिताम् sharp, शक्तिम् javelin, प्रगृह्य taking hold, मीनः fish, महार्णवम् इव like the ocean, वानरराजसैन्यम् Vanara kingdom army, आविवेश entered.

Then Naranthaka, mounted on horseback went at wind speed taking hold of javelin and entered Vanara army just as fish entered the ocean.