Valmiki Ramayana Bala Kanda Sarga 28 Shloka 16
Original Shlokaस च तान् राघवो ज्ञात्वा विश्वामित्रं महामुनिम्। गच्छन्नेवाथ मधुरं श्लक्ष्णं वचनमब्रवीत्।।1.28.16।।
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स: राघव: Rama, तान् ज्ञात्वा having acquired the knowledge of those weapons, अथ later, गच्छन्नेव while walking, विश्वामित्रं महामुनिम् maharshi Visvamitra, मधुरम् in gentle, श्लक्ष्णम् soft, वचनम् words, अब्रवीत् spoke.
After having acquired the knowledge of the weapons Rama addressed maharshi Viswamitra in gentle and soft words while walking along with him.