अत्र here, धर्मकोविदाः those wellversed in dharma, राजर्षयः royal saints, मृगयाम् hunting, यान्ति go for, वानर monkey, त्वम् you, अयुध्यन् while not fighting, प्रतियुध्यन् वा or while fighting back, यस्मात् since, शाखामृगः monkey, असि you are, तस्मात् therefore, मया myself, युद्धे in battle, बाणेन by an arrow, निहतः struck down.

'O monkey even royal saints wellversed in dharma go for hunting. I struck you down with an arrow whether you were fighting with Sugriva or not, since you are a monkey. (You can be hit whether you are fighting face to face or not).