Valmiki Ramayana Ayodhya Kanda Sarga 109 Shloka 24
Original Shlokaकथं ह्यहं प्रतिज्ञाय वनवासमिमं गुरॊ:। भरतस्य करिष्यामि वचो हित्वा गुरोर्वचः।।2.109.24।।
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अहम् I, इमं वनवासम् this dwelling in the forest, गुरौ to father, प्रतिज्ञाय having sworn, गुरोः father's, वचः words, हित्वा disregarding, भरतस्य Bharata's, वचः words, कथम् how, करिष्यामि shall I do?
Having sworn before my father that I would live in the forest, how can I act upon Bharata's request in disregard to my father's words?