Valmiki Ramayana Yuddha Kanda Sarga 69 Shloka 57
Original Shlokaवानरान्वानरैरेवजघ्नुस्तेनैरृतर्षभाः ।।6.69.57।। राक्षसान्राक्षसैरेवजघ्नुस्तेवानराअपि ।
1 source checked for this shloka
ते they, नैरृतर्षभाः bull of Rakshasas, वानरान् at Vanaras, वानरैरेव with monkeys, जघ्नुः struck, वानराः Vanaras अपि and also, राक्षसान् Rakshasas, राक्षसैरेव with Rakshasas, जघ्नुः struck.
The bull among Rakshasas struck at Vanaras with other Vanaras and the monkeys struck Rakshasas with other Rakshasas.