रामः Rama, अपि also, एषाम् these, द्रुमम् trees, एकेन with one, बाणेन with arrow, दारयेत् pierce through(split), रामस्य Rama's, विक्रमम् prowess, दृष्ट्वा on seeing, वालिनम् Vali, निहतम् killing, मन्ये I think, अपि also.

'If I see Rama splitting these trees with one arrow, I will believe he can kill Vali with his prowess.