Valmiki Ramayana Yuddha Kanda Sarga 45 Shloka 15

मर्मज्ञः vital, वीरः warrior, ततः thereafter, रामलक्ष्मणयोः Rama and Lakshmana, मर्मसु vital parts, निशितान् sharp, शरान् arrows, मज्जयन् digging, मुहुर्मुहुः again and again, ननादच kept roaring.

There after that warrior went on digging sharp arrows into the vital parts of Rama and Lakshmana again and again and kept roaring.