Valmiki Ramayana Ayodhya Kanda Sarga 104 Shloka 22
Original Shlokaएताभ्यां धर्मशीलाभ्यां वनं गच्छेति राघव। मातापितृभ्यामुक्तोऽहं कथमन्यत्समाचरे।।2.104.22।।
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राघव O Bharata, धर्मशीलाभ्याम् of righteous conduct, एताभ्याम् by these two, मातापितृभ्याम् by the father and mother, वनम् to forest, गच्छ go, इति thus, उक्तः having been told, अहम् I, अन्यत् other than this, कथम् how, समाचरेत् can act?
O Bharata, I have been commanded by our righteous father and mother to go to the forest. How can any one act otherwise?