Valmiki Ramayana Aranya Kanda Sarga 71 Shloka 26
Original Shlokaएवमुक्तस्तु रामेण वाक्यं दनुरनुत्तमम्।।3.71.26।। प्रोवाच कुशलो वक्तुं वक्तारमपि राघवम्।
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रामेण by Rama, एवम् in that way, उक्तः having been asked, वक्तुम् telling, कुशलः one who can speak well, दनुः Danu, वक्तारम् addressing one who can speak, राघवम् to Rama, अनुत्तमम् best, वाक्यम् word, प्रोवाच spoke.
Danu who was proficient in speech spoke with chosen words to Rama who was a great speaker himself: