Valmiki Ramayana Yuddha Kanda Sarga 64 Shloka 11

एकस्यैव you alone, अभियाने set out, त्वया by you, यः that, हेतुः reason, कथितः adduced, तत्रापि by you, यत् that, अनुपपन्नम् illconceived असाधु च improper, ते to you, वक्ष्यामि will reveal.

"You have set out alone (for war) and the reason adduced by you is ill conceived and improper. I shall tell you."